Wavelength converting component

Abstract

The present invention relates to a manufacturing method for a wavelength converting component which is prepared from a dispersion containing a crosslinkable ceramizable polymer material having a silazane repeating unit and at least one wavelength converting material. There are further provided wavelength converting components which can be used for converting blue, violet and/or UV light into light with a longer wavelength. There is also provided a light source and a lighting unit comprising said wavelength converting components.

Claims

1. A method of manufacturing a wavelength converting component, wherein the wavelength converting component contains at least one wavelength converting material and a matrix material, and wherein the method comprises the following steps: (a) providing a dispersion containing a crosslinkable ceramizable material and at least one wavelength converting material, wherein the crosslinkable ceramizable material is a polymer containing a silazane repeating unit M.sup.1; (b-1) precuring said dispersion at a first temperature of ≥150 to ≤250° C.; and (b-2) curing said precured dispersion at a second temperature of >300 to ≤500° C. to obtain a wavelength converting component; wherein the precuring in step (b-1) is carried out in a mold or on a plate and the precured dispersion is removed from the mold or plate before the curing in step (b-2) takes place; and wherein the curing in step (b-2) is carried out for ≥1 min to ≤24 h.

2. The method according to claim 1, wherein the silazane repeating unit M.sup.1 is represented by formula (I):
-[—SiR.sup.1R.sup.2—NR.sup.3—]-  (I) wherein R.sup.1, R.sup.2 and R.sup.3 are independently from each other hydrogen or alkyl.

3. The method according to claim 2, wherein R.sup.1, R.sup.2and R.sup.3 in formula (I) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms.

4. The method according to claim 2, wherein the polymer contains a further silazane repeating unit M.sup.2, wherein M.sup.2 is represented by formula (II):
-[—SiR.sup.4R.sup.5—NR.sup.6—]-  (II) wherein R.sup.4, R.sup.5 and R.sup.6 are independently from each other hydrogen or alkyl; and wherein M.sup.2 is different from M.sup.1.

5. The method according to claim 4, wherein R.sup.4, R.sup.5and R.sup.6 in formula (II) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms.

6. The method according to claim 2, wherein the polymer contains a further repeating unit M.sup.3, wherein M.sup.3 is represented by formula (III):
-[—SiR.sup.7R.sup.8—[O—SiR.sup.7R.sup.8—].sub.a—NR.sup.9—]-  (III) wherein R.sup.7, R.sup.8, R.sup.9 are independently from each other hydrogen or alkyl; and a is an integer from 1 to 60.

7. The method according to claim 6, wherein R.sup.7, R.sup.8and R.sup.9 in formula (III) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms.

8. The method according to claim 1, wherein the at least one wavelength converting material is selected from phosphors or converters based on semiconductor nanoparticles.

9. A wavelength converting component obtained by the method according to claim 1, wherein the matrix material contains Si—N bonds and wherein the matrix material has a density of ≥1.21 g/cm.sup.3 at 25° C., and wherein the matrix material shows a weight loss of ≤0.5 weight-%, upon heating from 25 to 350° C. under air atmosphere.

10. A wavelength converting component obtained by the method according to claim 1, wherein the matrix material contains Si—N bonds and wherein the matrix material has a density of ≥1.16 g/cm.sup.3 at 25° C., and wherein the matrix material shows a weight loss of ≤0.5 weight-%, upon heating from 25 to 350° C. under air atmosphere.

11. A wavelength converting component obtained by the method according to claim 1, wherein the matrix material contains Si—N bonds and wherein the matrix material has a coefficient of thermal expansion of ≤150 ppm/K in a temperature range from 25 to 80° C., and wherein the matrix material shows a weight loss of ≤0.5 weight-%, upon heating from 25 to 350° C. under air atmosphere.

12. A light source comprising a primary light source and a wavelength converting component according to claim 10.

13. A lighting unit which comprises at least one light source according to claim 12.

14. A method for the conversion of blue, violet and/or UV light from a primary light source into light with a longer wavelength comprising passing the light through a wavelength converting component of claim 9.

15. A method for the conversion of blue, violet and/or UV light from a primary light source into light with a longer wavelength, comprising passing the light through a wavelength converting component of claim 10.

16. A method for the conversion of blue, violet and/or UV light from a primary light source into light with a longer wavelength, comprising passing the light through a wavelength converting component of claim 11.

17. The lighting unit according to claim 13, which is a lighting unit for a projector or an automobile.

18. The method according to claim 1, wherein the mold is a PTFE mold or a PVDF mold and the plate is a PTFE plate or a PVDF plate.

19. The method according to claim 1, wherein said first temperature is ≥150 to ≤250° C., and said second temperature of >305 to ≤500° C.

20. The method according to claim 1, wherein the precuring in step (b-1) is carried out for a time period of ≥1 min to ≤10 h.

21. The method according to claim 1, wherein the precuring in step (b-1) is carried out for a time period of ≥1 hr to ≤10 h and the curing in step (b-2) is carried out for ≥1 hr to ≤24 h.

22. A light source comprising a primary light source and a wavelength converting component according to claim 11.

23. A lighting unit which comprises at least one light source according to claim 22.

24. The lighting unit according to claim 23, which is a lighting unit for a projector or an automobile.

25. A light source comprising a primary light source and a wavelength converting component according to claim 9.

26. A lighting unit which comprises at least one light source according to claim 25.

27. The lighting unit according to claim 26, which is a lighting unit for a projector or an automobile.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1: Schematic course of the curing and ceramization process of organopolysilazanes. The weight loss is shown as a function of the temperature.

(2) FIG. 2: Schematic drawing of a wavelength converting component used in an automotive lighting unit or in a projector lighting unit, e.g. in form of a colour wheel, in transmission mode.

(3) FIG. 3: Schematic drawing of a wavelength converting component used in an automotive lighting unit or in a projector lighting unit, e.g. in form of a colour wheel, in reflective mode.

(4) FIG. 4: Direct and remote arrangement of the wavelength converting component with respect to the primary light source (e.g. LED chip).

(5) FIG. 5: Wavelength converting component as plain platelet or lens-like part in a light source.

(6) FIG. 6: Placement of wavelength converting component on a LED wafer prior to dicing.

(7) FIG. 7: Placement of wavelength converting component on a singularized LED chip.

(8) FIG. 8: Temperature dependent coefficient of thermal expansion (CTE). .circle-solid.=average CTE in a temperature range from 25 to 80° C.; ◯=average CTE in a temperature range from 80 to 150° C.

(9) FIG. 9: Temperature dependent density. ◯=density.

(10) FIG. 10: Presence of organic groups and absence of Si—H groups detected by FT-IR. =condition A: material cured at 120° C. for 4 h; =condition B: A+additional heating at 200° C. for 24 h in air; =condition C: B+additional heating at 300° C. for 24 h in air; =condition D: C+additional heating at 350° C. for 24 h in air.

(11) FIG. 11: Thermogravimetric analysis (TGA) in air atmosphere with a heating rate of 10 K/min. =condition A: material cured at 120° C. for 4 h; =condition B: A+additional heating at 200° C. for 24 h in air; =condition C: B+additional heating at 250° C. for 24 h in air; =condition D: C+additional heating at 400° C. for 24 h in air.

(12) FIG. 12a: Emission spectrum of thiogallate in methyl silicone before and after storing for 500 h in a climate chamber at 85° C. and 85% relative humidity. =initial spectrum before storing; =spectrum after storing for 500 h in climate chamber at 85° C. and 85% relative humidity.

(13) FIG. 12b: Emission spectrum of thiogallate in organopolysilazane cured at 325° C. for 16 h before and after storing for 500 h in a climate chamber at 85° C. and 85% relative humidity. =initial spectrum before storing; =spectrum after storing for 500 h in climate chamber at 85° C. and 85% relative humidity.

(14) FIG. 13: Angular dependence of emitted light. =LED chip coated with a lens-shaped platelet. Intensity normalized to 100% at angle of 00; =LED chip coated with a plain platelet. Intensity normalized to 100% at angle of 0°.

(15) FIG. 14: PTFE mold used in Examples 5 and 6.

(16) FIG. 15: Glass plate used in Examples 7 to 10.

DETAILED DESCRIPTION

Definitions

(17) The term “crosslinking” as used herein refers to a crosslinking reaction which may be induced by any kind of energy such as e.g. heat and/or radiation, and/or a catalyst. A crosslinking reaction involves sites or groups on existing polymers or an interaction between existing polymers that results in the formation of a small region in a polymer from which at least three chains emanate. Said small region may be an atom, a group of atoms, or a number of branch points connected by bonds, groups of atoms or oligomeric or polymeric chains.

(18) The term “ceramizing” as used herein describes the preparation of a ceramic material from a ceramic precursor. Ceramic materials are based on inorganic, non-metallic solid materials comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds.

(19) The term “polymer” includes, but is not limited to, homopolymers, copolymers, for example, block, random, and alternating copolymers, terpolymers, quaterpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible configurational isomers of the material. These configurations include, but are not limited to isotactic, syndiotactic, and atactic symmetries. A polymer is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units (i.e. repeating units) derived, actually or conceptually, from molecules of low relative mass (i.e. monomers).

(20) The term “monomer” as used herein refers to a molecule which can undergo polymerization thereby contributing constitutional units (repeating units) to the essential structure of a polymer.

(21) The term “homopolymer” as used herein stands for a polymer derived from one species of (real, implicit or hypothetical) monomer.

(22) The term “copolymer” as used herein generally means any polymer derived from more than one species of monomer, wherein the polymer contains more than one species of corresponding repeating unit. In one embodiment the copolymer is the reaction product of two or more species of monomer and thus comprises two or more species of corresponding repeating unit. It is preferred that the copolymer comprises two, three, four, five or six species of repeating unit. Copolymers that are obtained by copolymerization of three monomer species can also be referred to as terpolymers. Copolymers that are obtained by copolymerization of four monomer species can also be referred to as quaterpolymers. Copolymers may be present as block, random, and/or alternating copolymers.

(23) The term “block copolymer” as used herein stands for a copolymer, wherein adjacent blocks are constitutionally different, i.e. adjacent blocks comprise repeating units derived from different species of monomer or from the same species of monomer but with a different composition or sequence distribution of repeating units.

(24) Further, the term “random copolymer” as used herein refers to a polymer formed of macromolecules in which the probability of finding a given repeating unit at any given site in the chain is independent of the nature of the adjacent repeating units. Usually, in a random copolymer, the sequence distribution of repeating units follows Bernoullian statistics.

(25) The term “alternating copolymer” as used herein stands for a copolymer consisting of macromolecules comprising two species of repeating units in alternating sequence.

(26) The term “polysilazane” as used herein refers to a polymer in which silicon and nitrogen atoms alternate to form the basic backbone. Since each silicon atom is bound to at least one nitrogen atom and each nitrogen atom to at least one silicon atom, both chains and rings of the general formula [R.sup.1R.sup.2Si—NR.sup.3].sub.m occur, wherein R.sup.1 to R.sup.3 are independently from each other hydrogen atoms or organic substituents; and m is an integer. If all substituents R.sup.1 to R.sup.3 are H atoms, the polymer is designated as perhydropolysilazane, polyperhydrosilazane or inorganic polysilazane ([H.sub.2Si—NH].sub.m). If at least one substituent R.sup.1 to R.sup.3 is an organic substituent, the polymer is designated as organopolysilazane.

(27) The term “polysiloxazane” as used herein refers to a polysilazane which additionally contains sections in which silicon and oxygen atoms alternate. Such section may be represented for example by [O—SiR.sup.4R.sup.5].sub.n, wherein R.sup.4 and R.sup.5 can be hydrogen atoms or organic substituents; and n is an integer. If all substituents of the polymer are H atoms, the polymer is designated as perhydropolysiloxazane. If at least one substituents of the polymer is an organic substituent, the polymer is designated as organopolysiloxazane.

(28) Polymers having a silazane repeating unit [R.sup.1R.sup.2Si—NR.sup.3].sub.m as described above are typically referred to as polysilazanes or polysiloxazanes. While polysilazanes are composed of one or more different silazane repeating units, polysiloxazanes additionally contain one or more different siloxane repeating unit [O—SiR.sup.4R.sup.5].sub.n as described above. The structure of polysilazanes or polysiloxazanes usually contains not only linear sections, but also separate or condensed rings and complex three-dimensional arrangements. Polysilazanes and polysiloxazanes contain tertiary nitrogen atoms “Si.sub.3N” (with respect to silicon) and possibly primary nitrogen atoms “SiNR.sub.2” and secondary nitrogen atoms “Si.sub.2NR”. Likewise, they contain tertiary silicon atoms “N.sub.3SiR” (with respect to nitrogen) and possibly primary silicon atoms “NSiR.sub.3” and secondary silicon atoms “N.sub.2SiR.sub.2”. The exact structure may vary depending on the specific synthesis and the nature of the substituents R.

(29) Polysilazanes and polysiloxazanes are usually liquid polymers which become solid at molecular weights of ca.>10,000 g/mol. In most applications liquid polymers of moderate molecular weights, typically in the range from 2,000 to 8,000 g/mol, are used. For preparing a solid coating from such liquid polymers, a crosslinking reaction is required.

(30) Polysilazanes or polysiloxazanes are crosslinked by hydrolysis reactions, wherein moisture and optionally oxygen from the air reacts according to the mechanisms shown by Equations (I) and (II).

(31) Hydrolysis or oxidation of Si—N and Si—H occurs, if water and optionally oxygen is present:
R.sup.3Si—NH—SiR.sub.3+H.sub.2O.fwdarw.R.sup.3Si—O—SiR.sub.3+NH.sub.3  (Equation (I))
R.sup.3Si—H+H-SiR.sub.3+H.sub.2O/O.sub.2.fwdarw.R.sup.3Si—O—SiR.sub.3+2H.sub.2/H.sub.2O  (Equation (11))

(32) Crosslinking may also occur by loss of hydrogen according to the mechanism shown by Equation (III).

(33) Crosslinking by loss of hydrogen:
R.sup.3Si—NH—SiR.sub.3+R.sup.3Si—H.fwdarw.R.sup.3Si—N(—SiR.sub.3).sub.2+H.sub.2  (Equation (III))

(34) During the above crosslinking reactions there is an increase in molecular weight and the material becomes solid. The crosslinking thus leads to a curing of the polysilazane or polysiloxazane material. For this reason, the terms “curing” and “crosslinking” and the corresponding verbs “cure” and “crosslink” are interchangeably used as synonyms in the present application when referred to silazane based polymers such as e.g. polysilazanes and polysiloxazanes.

(35) Usually, crosslinking is performed by hydrolysis and starts at ambient conditions (20 to 25° C.) or at elevated temperatures of ≥150 to ≤250° C. To achieve complete crosslinking higher temperatures are required. The present inventors found by IR analysis that the Si—H and N—H bonds in silazane based polymers completely disappear when heating the material to temperatures of >250 to ≤500° C., preferably >280 to ≤500° C., more preferably >300 to ≤500° C., still more preferably ≥305 to ≤500° C. and most preferably ≥310 to ≤500° C. These temperature ranges are therefore used for the curing in step (b) of the manufacturing method according to the present invention.

(36) In a preferred embodiment, the manufacturing method according to the present invention provides a two-stage curing process, wherein a precuring step (b-1) is conducted at a first temperature of ≥150 to ≤250° C., preferably ≥150 to ≤200° C., followed by a curing step (b-2) at a second temperature of >250 to ≤500° C., preferably >280 to ≤500° C., more preferably >300 to ≤500° C., still more preferably ≥305 to ≤500° C. and most preferably ≥310 to ≤500° C.

(37) If crosslinked organopolysilazanes or organopolysiloxazanes, where at least one substituent R is a carbon-containing substituent, are further heated to temperatures of >500° C., carbon is released as methane or carbon dioxide depending on the atmosphere conditions and a silicon-nitride type or silicon-oxynitride type ceramic is formed.

(38) However, it is preferred that such ceramization does not form part of the manufacturing method of the present invention. Thus, it is preferred that the manufacturing method does not contain any further heat treatment in addition to the curing in step (b). In a preferred embodiment, the manufacturing method does not contain a heat treatment step, where temperatures of >500° C. are applied.

(39) The same applies mutatis mutandis to the manufacturing method when a two-stage curing process is applied, wherein a precuring step (b-1) is conducted, followed by a curing step (b-2) as described above. In this case, it is preferred that the manufacturing method does not contain any further heat treatment in addition to steps (b-1) and (b-2). In a preferred embodiment, the manufacturing method does not contain a heat treatment step, where temperatures of >500° C. are applied.

(40) A crosslinkable and ceramizable material within the meaning of the present invention is a polymer containing at least one silazane repeating unit M.sup.1 which undergoes at least the transformations shown by Equations (I) to (III) when heated up to temperatures of ≤500° C. The crosslinkable ceramizable material may be ceramized at temperatures of >500° C. which means that carbon is released as described above.

(41) FIG. 1 provides a schematic view on the course of the curing and ceramization process of organopolysilazanes. The weight loss is shown as a function of the temperature.

(42) The term “LED” as used herein refers to light emitting devices comprising one or more of a light emitting source, lead frame, wiring, solder (flip chip), converter, filling material, encapsulation material, primary optics and/or secondary optics. Semiconductor light emitting sources may be selected from semiconductor light emitting diodes (LED chips) or semiconductor laser diodes (LD chips). The converter and encapsulation material may form a wavelength converting component which may additionally contain a filling material. An LED may be prepared from an LED precursor containing a semiconductor light source (LED chip) and/or lead frame and/or gold wire and/or solder (flip chip) on which a wavelength converting component is mounted. Such wavelength converting component may be either arranged directly on an LED chip or alternatively arranged remote therefrom, depending on the respective type of application (FIG. 4).

(43) The term “high power LED” as used herein refers to an LED comprising an LED chip, which is operated at a current density of >350 mA per 1 mm.sup.2 to ≤1000 mA per 1 mm.sup.2 chip area.

(44) The term “ultra-high power LED” as used herein refers to an LED comprising an LED chip, which is operated at current density of >1000 mA per 1 mm.sup.2 chip area.

(45) The term “laser LED” as used herein refers to an LED comprising an LD chip.

(46) The term “wavelength converting material” or briefly referred to as a “converter” means a material that converts light of a first wavelength to light of a second wavelength, wherein the second wavelength is different from the first wavelength. Wavelength converting materials are phosphors and semiconductor nanoparticles.

(47) A “phosphor” is a fluorescent inorganic material which contains one or more light emitting centers. The light emitting centers are formed by activator elements such as e.g. atoms or ions of rare earth metal elements, for example La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and/or atoms or ions of transition metal elements, for example Cr, Mn, Fe, Co, Ni, Cu, Ag, Au and Zn, and/or atoms or ions of main group metal elements, for example Na, Tl, Sn, Pb, Sb and Bi. Examples of suitable phosphors include phosphors based on garnet, silicate, orthosilicate, thiogallate, sulfide, nitride, silicon-based oxynitride, nitridosilicate, nitridoaluminumsilicate, oxonitridosilicate, oxonitridoaluminumsilicate and rare earth doped sialon. Phosphors within the meaning of the present application are materials which absorb electromagnetic radiation of a specific wavelength range, preferably blue and/or ultraviolet (UV) electromagnetic radiation, and convert the absorbed electromagnetic radiation into electromagnetic radiation having a different wavelength range, preferably visible (VIS) light such as violet, blue, green, yellow, orange or red light.

(48) The term “semiconductor nanoparticle” in the present application denotes a crystalline nanoparticle which consists of a semiconductor material. Semiconductor nanoparticles are also referred to as quantum materials in the present application. They represent a class of nanomaterials with physical properties that are widely tunable by controlling particle size, composition and shape. Among the most evident size dependent property of this class of materials is the tunable fluorescence emission. The tunability is afforded by the quantum confinement effect, where reducing particle size leads to a “particle in a box” behavior, resulting in a blue shift of the band gap energy and hence the light emission. For example, in this manner, the emission of CdSe nanocrystals can be tuned from 660 nm for particles of diameter of ˜6.5 nm, to 500 nm for particles of diameter of ˜2 nm. Similar behavior can be achieved for other semiconductors when prepared as nanocrystals allowing for broad spectral coverage from the UV (using ZnSe, CdS for example) throughout the visible (using CdSe, InP for example) to the near-IR (using InAs for example).

(49) Suitable semiconductor materials are selected from groups II-VI, III-V, IV-VI or I-III-VI.sub.2 or any desired combination of one or more thereof. For example, the semiconductor material may be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, GaAs, GaP, GaAs, GaSb, GaN, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, AlSb, Cu.sub.2S, Cu.sub.2Se, CuGaS.sub.2, CuGaSe.sub.2, CuInS.sub.2, CuInSe.sub.2, Cu.sub.2(InGa)S.sub.4, AglnS.sub.2, AglnSe.sub.2, Cu.sub.2(ZnSn)S.sub.4, alloys thereof and mixtures thereof.

(50) Semiconductor nanoparticles are any desired discrete units having at least one dimension in the sub-micron size, which, in some embodiments, is less than 100 nm and in some other embodiments has a size of less than one micron as the largest dimension (length). In some other embodiments, the dimension is less than 400 nm. The semiconductor nanoparticle can have any desired symmetrical or asymmetrical geometrical shape, and non-restrictive examples of possible shapes are elongate, round, elliptical, pyramidal, etc. A specific example of a semiconductor nanoparticle is an elongate nanoparticle, which is also called a nanorod and is made from a semiconducting material. Further semiconductor nanorods which can be used are those having a metal or metal-alloy region on one or both ends of the respective nanorod. Examples of such elongate semiconductor/metal nanoparticles and the production thereof are described in WO 2005/075339, the disclosure content of which is incorporated herein by way of reference. Other possible semiconductor/metal nanoparticles are shown in WO 2006/134599, the disclosure content of which is incorporated herein by way of reference.

(51) Furthermore, semiconductor nanoparticles in a core/shell configuration or a core/multishell configuration are known. These are discrete semiconductor nanoparticles which are characterized by a heterostructure, in which a “core” comprising one type of material is covered with a “shell” comprising another material. In some cases, the shell is allowed to grow on the core, which serves as “seed core”. The core/shell nanoparticles are then also referred to as “seeded” nanoparticles. The expression “seed core” or “core” relates to the innermost semiconductor material present in the hetero-structure. Known semiconductor nanoparticles in core/shell configuration are shown, for example, in EP 2 528 989 B1, the contents of which are incorporated into the present description in their totality by way of reference.

(52) The semiconductor nanoparticles may be also employed as semiconductor nanoparticles on the surface of non-activated crystalline materials. In such converters, one or more types of semiconductor nanoparticles (quantum materials) are located on the surface of one or more types of non-activated crystalline materials.

(53) As used herein, the term “non-activated crystalline material” denotes an inorganic material in particle form which is crystalline and does not have an activator, i.e. light converting centers. The non-activated crystalline material is thus itself neither luminescent nor fluorescent. In addition, it has no specific inherent absorption in the visible region and is consequently colourless. Furthermore, the non-activated crystalline material is transparent. The non-activated crystalline material serves as support material for the semiconductor nanoparticles. Owing to the lack of colour and the transparency of the non-activated crystalline material, light emitted by a primary light source or by another wavelength converting material is able to pass through the material unhindered and with no losses.

(54) Preferred non-activated crystalline materials are matrix materials of an inorganic phosphor selected from non-activated crystalline metal oxides, non-activated crystalline silicates and halosilicates, non-activated crystalline phosphates and halophosphates, non-activated crystalline borates and borosilicates, non-activated crystalline aluminates, gallates and alumosilicates, non-activated crystalline molybdates and tungstates, non-activated crystalline sulfates, sulfides, selenides and tellurides, non-activated crystalline nitrides and oxynitrides, non-activated crystalline SiAlONs and other non-activated crystalline materials, such as non-activated crystalline complex metal-oxygen compounds, non-activated crystalline halogen compounds and non-activated crystalline oxy compounds, such as preferably oxysulfides or oxychlorides.

(55) Suitable semiconductor nanoparticles on non-activated crystalline materials are described in WO 2017/041875 A1 the disclosure of which is hereby incorporated by reference.

(56) The term “encapsulation material” or “encapsulant” as used herein means a material which covers or encloses a wavelength converting material. The encapsulation material may be regarded as a matrix embedding the converter particles. Preferably, the encapsulation material forms part of a wavelength converting component (or briefly converter component) which contains one or more wavelength converting materials and optionally one or more filling materials. The encapsulation material forms a barrier against the external environment of the LED, thereby protecting the converter and/or the LED chip. External environmental influences against which the encapsulation material needs to protect the LED may be chemical such as moisture, acids, bases, oxygen, etc. or physical such as temperature, mechanical impact, or stress. The encapsulation material usually acts as a binder for the converter. The encapsulating material is preferably in direct contact with the converter and/or the LED chip. Usually, the encapsulation material forms part of an LED package comprising an LED chip and/or lead frame and/or gold wire, and/or solder (flip chip), the filling material, converter and a primary and secondary optic. The encapsulation material may fully or partially cover an LED chip and/or lead frame and/or gold wire.

(57) The term “wavelength converting component” as used herein means a component for a light emitting device, such as e.g. a high power LED, an ultra-high power LED or a laser LED, comprising at least one wavelength converting material and an encapsulation material as matrix material embedding the wavelength converting material. The wavelength converting component may optionally contain one or more filler materials. The wavelength converting component may be formed as a three-dimensional molding having a complex surface shape with recesses, cavities, projections, etc. which cannot be made by grinding of (single) crystals or which can be made with sintered ceramics only to a certain extent while being rather expensive. Furthermore, different shapes allow specific beamforming effects such as e.g. lens effect, scattering effect, lightguide effect and/or uniform spatial distribution of light colour temperature which cannot be realized with ceramics for cost reasons. The wavelength converting component may be either arranged directly on a semiconductor light source (LED chip) or alternatively arranged remote therefrom, depending on the respective type of application (FIG. 4).

(58) The term “Lewis acid” as used herein means a molecular entity (and the corresponding chemical species) that is an electron-pair acceptor and therefore able to react with a Lewis base to form a Lewis adduct, by sharing the electron pair furnished by the Lewis base. A “Lewis base” as used herein is a molecular entity (and the corresponding chemical species) that is able to provide a pair of electrons and thus capable of coordination to a Lewis acid, thereby forming a Lewis adduct. A “Lewis adduct” is an adduct formed between a Lewis acid and a Lewis base.

PREFERRED EMBODIMENTS

(59) Method of Manufacturing

(60) The present invention relates to a method of manufacturing a wavelength converting component containing at least one wavelength converting material and a matrix material, wherein the method comprises the following steps:

(61) (a) providing a dispersion containing a crosslinkable ceramizable material and at least one wavelength converting material, wherein the crosslinkable ceramizable material is a polymer containing a silazane repeating unit M.sup.1; and

(62) (b) curing said dispersion at a temperature of >250 to ≤500° C., preferably at a temperature of >280 to ≤470° C., more preferably at a temperature of >300 to ≤450° C., still more preferably at a temperature of ≥305 to ≤425° C. and most preferably at a temperature of ≥310 to ≤400° C., to obtain a wavelength converting component.

(63) In a preferred embodiment the curing in step (b) is carried out for a time period of >0 to ≤24 h, preferably for a time period of ≥1 min to ≤24 h, more preferably for a time period of ≥1 h to ≤24 h and most preferably for a time period of ≥2 h to ≤24 h.

(64) It is preferred that the curing in step (b) is carried out on a hot plate, in a furnace or by IR radiation.

(65) In a preferred embodiment, the manufacturing method according to the present invention provides a two-stage curing process, wherein a precuring step (b-1) is conducted at a first temperature of ≥150 to ≤250° C., preferably at a temperature of ≥150 to ≤200° C., followed by a curing step (b-2) at a second temperature of ≥250 to ≤500° C., preferably at a temperature of >280 to ≤470° C., more preferably at a temperature of >300 to ≤450° C., still more preferably ≥305 to ≤425° C. and most preferably at a temperature of ≥310 to ≤400° C. It is preferred that the curing step is directly following the precuring step.

(66) In a preferred embodiment the manufacturing method of the present invention does not contain any further heat treatment apart from the curing step (b) or the precuring step (b-1) and the curing step (b-2), respectively. Hence, no further crosslinking and/or ceramization takes place in this preferred embodiment. It is particularly preferred that the manufacturing method does not contain a heat treatment step, where temperatures of >500° C. are applied.

(67) In a preferred embodiment the precuring in step (b-1) is carried out for a time period of >0 to ≤10 h, preferably for a time period of ≥1 min to ≤10 h, more preferably for a time period of ≥1 h to ≤10 h and most preferably for a time period of ≥2 h to ≤10 h. In a preferred embodiment the curing in step (b-2) is carried out for a time period of >0 to ≤24 h, preferably for a time period of ≥1 min to ≤24 h, more preferably for a time period of ≥1 h to ≤24 h and most preferably for a time period of ≥2 h to ≤24 h.

(68) It is preferred that the precuring step (b-1) is followed directly by the curing step (b-2). Directly shall mean in this context that the curing step (b-2) follows immediately the precuring step (b-1) and that there is no further step in-between where a substantial change of the chemical composition and/or physical properties of the precured dispersion takes place.

(69) It is preferred that the precuring in step (b-1) is carried out on a hot plate, in a furnace or by IR radiation.

(70) It is preferred that the curing in step (b-2) is carried out on a hot plate, in a furnace or by IR radiation.

(71) The material which is obtained after the curing in step (b) or step (b-1), i.e. the wavelength converting component, contains the at least one wavelength converting material embedded in a matrix material. The matrix material is formed by curing the crosslinkable polymer material containing a silazane repeating unit M.sup.1. The matrix material embedding the at least one wavelength converting material contains Si—N bonds and is also referred to as “semi-ceramic material” in the present invention.

(72) The present inventors found that fully cured silazane based polymers form a semi-ceramic material which is useful as an easy to synthesize substitute for conventional wavelength converting ceramics offering much more flexibility in the choice of type and mixture of wavelength converting material, in the colour point and in the geometric shape of the component. The semi-ceramic material is synthesized at temperatures of equal or more than 250° C. and less than 500° C. Therefore, the synthesis temperature is higher or at least as high as the temperature to which the material is exposed to in a high power LED, ultra-high power LED or laser LED. All chemical transformations for curing are finished and practically no change takes place anymore during the operational lifetime of the LED which imparts an excellent colour point stability.

(73) Preferably, the polymer, which is used as crosslinkable ceramizable material, contains a repeating unit M.sup.1 and a further repeating unit M.sup.2, wherein M.sup.1 and M.sup.2 are silazane units which are different from each other. Preferably, the polymer contains a repeating unit M.sup.1 and a further repeating unit M.sup.3, wherein M.sup.1 is a silazane unit and M.sup.3 is a siloxazane unit. More preferably, the polymer contains a repeating unit M.sup.1, a further repeating unit M.sup.2 and a further repeating unit M.sup.3, wherein M.sup.1 and M.sup.2 are silazane units which are different from each other and M.sup.3 is a siloxazane unit.

(74) In a preferred embodiment the polymer, which is used as crosslinkable ceramizable material, is a polysilazane. Preferably, the polysilazane contains a repeating unit M.sup.1 and optionally a further repeating unit M.sup.2, wherein M.sup.1 and M.sup.2 are silazane repeating units which are different from each other. It is preferred that at least one of M.sup.1 and M.sup.2 is an organosilazane unit so that the crosslinkable ceramizable material is an organopolysilazane.

(75) In an alternative preferred embodiment the polymer, which is used as crosslinkable ceramizable material, is a polysiloxazane. Preferably, the polysiloxazane contains a repeating unit M.sup.1 and a further repeating unit M.sup.3, wherein M.sup.1 is a silazane unit and M.sup.3 is a siloxazane unit. More preferably, the polysiloxazane contains a repeating unit M.sup.1, a further repeating unit M.sup.2 and a further repeating unit M.sup.3, wherein M.sup.1 and M.sup.2 are silazane units which are different from each other and M.sup.3 is a siloxazane unit. It is preferred that at least one of M.sup.1 and M.sup.2 is an organosilazane unit so that the crosslinkable ceramizable material is an organopolysiloxazane.

(76) In a particularly preferred embodiment the polymer, which is used as crosslinkable ceramizable material, is a mixture of a polysilazane and a polysiloxazane as defined above. In a most preferred embodiment the polymer is a mixture of an organopolysilazane and organopolysiloxazane.

(77) It is preferred that the crosslinkable ceramizable material undergoes ceramization after having been cross-linked when the temperature is further increased to >500° C.

(78) As noted above, the crosslinkable ceramizable material is a polymer containing a silazane repeating unit M.sup.1. Preferably, the silazane repeating unit M.sup.1 is represented by formula (I):
-[—SiR.sup.1R.sup.2—NR.sup.3—]-  (I)
wherein R.sup.1, R.sup.2 and R.sup.3 are independently from each other hydrogen or alkyl.

(79) It is preferred that R.sup.1, R.sup.2 and R.sup.3 in formula (I) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms. More preferably, R.sup.1, R.sup.2 and R.sup.3 are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 6 carbon atoms, branched-chain alkyl having 3 to 6 alkyl atoms and cycloalkyl having 3 to 6 carbon atoms. Most preferably, R.sup.1, R.sup.2 and R.sup.3 are independently from each other hydrogen, methyl, ethyl, propyl, butyl, pentyl or hexyl.

(80) In a preferred embodiment, the polymer contains besides the silazane repeating unit M.sup.1 a further repeating unit M.sup.2 which is represented by formula (II):
-[—SiR.sup.4R.sup.5—NR.sup.6—]-  (II)
wherein R.sup.4, R.sup.5 and R.sup.6 are independently from each other hydrogen or alkyl; and wherein M.sup.2 is different from M.sup.1.

(81) It is preferred that R.sup.4, R.sup.5 and R.sup.6 in formula (II) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms. More preferably, R.sup.4, R.sup.5 and R.sup.6 are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 6 carbon atoms, branched-chain alkyl having 3 to 6 carbon atoms and cycloalkyl having 3 to 6 carbon atoms. Most preferably, R.sup.4, R.sup.5 and R.sup.6 are independently from each other hydrogen, methyl, ethyl, propyl, butyl, pentyl or hexyl.

(82) In a further preferred embodiment, the polymer is a polysiloxazane which contains besides the silazane repeating unit M.sup.1 a further repeating unit M.sup.3 which is represented by formula (III):
-[—SiR.sup.7R.sup.8—[O—SiR.sup.7R.sup.8—].sub.a—NR.sup.9—]-  (III)
wherein R.sup.7, R.sup.8, R.sup.9 are independently from each other hydrogen or organyl; and a is an integer from 1 to 60, preferably from 1 to 50. More preferably, a may be an integer from 5 to 50 (long chain monomer M.sup.3); or a may be an integer from 1 to 4 (short chain monomer M.sup.3).

(83) It is preferred that R.sup.7, R.sup.8 and R.sup.9 in formula (III) are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 12 carbon atoms, branched-chain alkyl having 3 to 12 carbon atoms and cycloalkyl having 3 to 12 carbon atoms. More preferably, R.sup.7, R.sup.8 and R.sup.9 are independently from each other selected from the group consisting of hydrogen, straight-chain alkyl having 1 to 6 carbon atoms, branched-chain alkyl having 3 to 6 carbon atoms and cycloalkyl having 3 to 6 carbon atoms. Most preferably, R.sup.7, R.sup.8 and R.sup.9 are independently from each other hydrogen, methyl, ethyl, propyl, butyl, pentyl or hexyl.

(84) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 the straight-chain alkyl groups, branched-chain alkyl groups and cycloalkyl groups may be substituted with one or more substituents R.sub.S which may be the same or different from each other, wherein R.sub.S is selected from F, Cl and SiMe.sub.3.

(85) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 it is more preferred that the straight-chain alkyl groups, branched-chain alkyl groups and cycloalkyl groups are not substituted.

(86) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 it is preferred that the they are independently selected from hydrogen, straight-chain alkyl and branched-chain alkyl.

(87) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 it is more preferred that they are independently selected from hydrogen and straight-chain alkyl.

(88) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 preferred straight-chain alkyl groups are methyl, ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl.

(89) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 preferred branched-chain alkyl groups may be selected from iso-propyl (1-methylethyl), sec-butyl (1-methylpropyl), iso-butyl (2-methylpropyl), tert-butyl (1,1-dimethylethyl), sec-pentyl (pentan-2-yl), 3-pentyl (pentan-3-yl), iso-pentyl (3-methyl-butyl), neo-pentyl (2,2-dimethyl-propyl) and tert-pentyl (2-methylbutan-2-yl), more preferably from iso-propyl (1-methylethyl), sec-butyl (1-methylpropyl), iso-butyl (2-methylpropyl) and tert-butyl (1,1-dimethylethyl).

(90) With respect to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 preferred cycloalkyl groups may be selected from cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

(91) It is understood that the skilled person can freely combine the above-mentioned preferred, more preferred and most preferred embodiments relating to the substituents R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 in the polymer in any desired way.

(92) Preferably, the polymer used as crosslinkable ceramizable material is a copolymer such as a random copolymer or a block copolymer or a copolymer containing at least one random sequence section and at least one block sequence section. More preferably, the polymer is a random copolymer or a block copolymer.

(93) It is preferred that the polymer used as crosslinkable ceramizable material is an organopolysilazane, wherein at least one of the substituents R.sup.1, R.sup.2 and R.sup.3 is a straight-chain alkyl group, a branched-chain alkyl group or a cycloalkyl group.

(94) It is preferred that the polymer used as crosslinkable ceramizable material is an organopolysiloxazane, wherein at least one of the substituents R.sup.1, R.sup.2 and R.sup.3 is a straight-chain alkyl group, a branched-chain alkyl group or a cycloalkyl group.

(95) Preferably, the polymers used in the present invention as crosslinkable ceramizable material have a molecular weight M.sub.w, as determined by GPC, of at least 1,000 g/mol, more preferably of at least 2,000 g/mol, even more preferably of at least 3,000 g/mol. Preferably, the molecular weight M.sub.w of the polymers is less than 100,000 g/mol. More preferably, the molecular weight M.sub.w of the polymers is in the range from 3,000 to 50,000 g/mol.

(96) Preferably, the total content of the polymer in the dispersion is in the range from 1 to 99.5% by weight, preferably from 5 to 99% by weight.

(97) In a preferred embodiment, the dispersion contains one or more solvents. Suitable solvents for the dispersion are, in particular, organic solvents which contain no water and also no reactive groups such as hydroxyl groups. These solvents are, for example, aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, esters such as ethyl acetate or butyl acetate, ketones such as acetone or methyl ethyl ketone, ethers such as tetrahydrofuran or dibutyl ether, and also mono- and polyalkylene glycol dialkyl ethers (glymes), or mixtures of these solvents.

(98) The dispersion is liquid and can be poured into molds to make parts of various geometries. Alternatively it can be coated directly onto the LED wafer (wafer level coating). The conversion to a semi-ceramic material needs much milder conditions of temperature not more than 500° C. and no pressure.

(99) In a preferred embodiment, the dispersion contains a curing catalyst. The curing catalyst is able to accelerate the crosslinking reactions according to Equations (I) to (III). Suitable curing catalysts are Lewis acids as described in the unpublished EP patent application No. 16201984.8.

(100) In a particularly preferred embodiment the Lewis acid curing catalyst in the dispersion is selected from the group consisting of triarylboron compounds such as e.g. B(C.sub.6H.sub.5).sub.3 and B(C.sub.6F.sub.5).sub.3, triarylaluminum compounds such as e.g. Al(C.sub.6H.sub.5).sub.3 and Al(C.sub.6F.sub.5).sub.3, palladium acetate, palladium acetylacetonate, palladium propionate, nickel acetylacetonate, silver acetylacetonate, platinum acetylacetonate, ruthenium acetylacetonate, ruthenium carbonyls, copper acetylacetonate, aluminum acetylacetonate, and aluminum tris(ethyl acetoacetate).

(101) Depending on the catalyst system used, the presence of moisture or oxygen may play a role in the curing of the crosslinkable ceramizable material. For instance, through the choice of a suitable catalyst system, it is possible to achieve rapid curing at high or low atmospheric humidity or at high or low oxygen content. The skilled worker is familiar with these influences and will adjust the atmospheric conditions appropriately by means of suitable optimization methods.

(102) Preferably, the amount of the Lewis acid curing catalyst in the dispersion is ≤10 weight-%, more preferably ≤5.0 weight-%, and most preferably ≤1.00 weight-%. Preferred ranges for the amount of the curing catalyst in the dispersion are from 0.001 to 10 weight-%, more preferably from 0.001 to 5.0 weight-%, and most preferably from 0.001 to 1.00 weight-%.

(103) Preferably, the formulation may comprise one or more additives selected from the group consisting of fillers, nanoparticles, viscosity modifiers, surfactants, additives influencing film formation, additives influencing evaporation behavior and cross-linkers.

(104) Preferred fillers are glass particles which preferably have a particle diameter of <10 μm. Such fillers may further improve the mechanical stability of the wavelength converting component. Preferred nanoparticles are selected from nitrides, titanates, diamond, oxides, sulfides, sulfites, sulfates, silicates and carbides which may be optionally surface-modified with a capping agent. Preferably, nanoparticles are materials having a particle diameter of <100 nm, more preferably <80 nm, even more preferably <60 nm, even more preferably <40 nm, and most more preferably <20 nm. The particle diameter may be determined by any standard method known to the skilled person.

(105) If the refractive index of the wavelength converting component is to be further increased, it is preferred to add selected nanoparticles having a refractive index of >2.0. Such selected nanoparticles are for example TiO.sub.2 and ZrO.sub.2. The refractive index may be determined by any standard method known to the skilled person.

(106) Since LED packages have a limited temperature stability and should not be exposed to temperature of >200° C., it is preferred that the curing of the dispersion in step (b) takes place on a support separately from the LED package. The wavelength converting component may then be detached from the support and afterwards attached to the LED chip or LD chip. This can be done, for example by small amounts of 90% PHPS in di-n-butylether which are dropped on top of the LED chip or LD chip. The wavelength converting component, which may be present in form of a platelet, is then positioned on the PHPS-wet chip and the LED package is then heated to temperatures of 100 to 200° C. for 1 to 8 h to cure the PHPS layer.

(107) The support on which the curing preferably takes place is a base which carries the dispersion provided in step (a). In a preferred embodiment of the present invention the support is selected from the list consisting of a sheet, a foil, a plate and a mold. In a particularly preferred embodiment the support is a mold. Preferred materials of which the sheet, foil, plate and mold are made of are glass, ceramics, plastics and metal. A preferred plastics is a fluoropolymer such as e.g. polytetrafluorethylene (PTFE) or polyvinylidene fluoride (PVDF). A preferred metal is aluminum, more preferably aluminum with a fluoropolymer coating. PTFE or PVDF is particularly useful, if the wavelength converting component is to be detached from the support.

(108) If the mechanical stability of the wavelength converting component is to be further increased, it is possible to cure the dispersion on a transparent substrate, for example a thin glass plate, or to attach the wavelength converting component after curing on such a transparent substrate. Thin glass plates have a thickness in the range of 10 μm to 300 μm.

(109) The dispersion may be applied to the support by any known application method such as, for example, casting, dispensing, screen printing, stencil printing, spray coating, spin coating, slot coating and ink-jet printing.

(110) In a preferred embodiment of the present invention, the precuring in step (b-1) and the curing in step (b-2) takes place on a support.

(111) In a particularly preferred embodiment of the present invention, the precuring in step (b-1) takes place on a support and the precured dispersion is detached from the support before the curing in step (b-2) takes place.

(112) In a particularly preferred embodiment of the present invention, the precuring in step (b-1) is carried out in a mold and the precured dispersion is removed from the mold before the curing in step (b-2) takes place.

(113) Preferably, the wavelength converting material is a substance having luminescent properties such as a phosphor or semiconductor nanoparticles. More preferably, the semiconductor nanoparticles are located on the surface of a non-activated crystalline material. The term “luminescent” is intended to include both, phosphorescent as well as fluorescent.

(114) For the purposes of the present application, the type of phosphor is not particularly limited. Suitable phosphors are well known to the skilled person and can easily be obtained from commercial sources. For the purposes of the present application the term “phosphor” is intended to include materials that absorb in one wavelength of the electromagnetic spectrum and emit at a different wavelength.

(115) Examples of suitable phosphors are inorganic fluorescent materials in particle form comprising one or more emitting centers. Such emitting centers may, for example, be formed by the use of so-called activators, which are preferably atoms or ions selected from the group consisting of rare earth elements, transition metal elements, main group elements and any combination of any of these. Example of suitable rare earth elements may be selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Examples of suitable transition metal elements may be selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Ag, Au and Zn. Examples of suitable main group elements may be selected from the group consisting of Na, Tl, Sn, Pb, Sb and Bi. Examples of suitable phosphors include phosphors based on garnet, silicate, orthosilicate, thiogallate, sulfide, nitride, silicon-based oxynitride, nitridosilicate, nitridoaluminumsilicate, oxonitridosilicate, oxonitridoaluminumsilicate and rare earth doped sialon.

(116) Suitable yellow phosphors may, for example, comprise or be based on (Gd,Y).sub.3(Al, Ga).sub.5O.sub.12 doped with Ce, such as the commercially available cerium-doped yttrium aluminum garnet (frequently abbreviated as “Ce:YAG” or “YAG:Ce”); or Th.sub.3-xM.sub.xO.sub.12:Ce (TAG) with M being selected from the group consisting of Y, Gd, La and Lu; or Sr.sub.2-x-yBa.sub.xCa.sub.ySiO.sub.4:Eu.

(117) Examples of green phosphors may be selected from the group of SrGa.sub.2S.sub.4:Eu; Sr.sub.2-yBa.sub.ySiO.sub.4:Eu and/or SrSi.sub.2O.sub.2N.sub.2:Eu.

(118) Phosphors which may be employed as converter in the converting layer of the LED are, for example: Ba.sub.2SiO.sub.4:Eu.sup.2+, BaSi.sub.2O.sub.5:Pb.sup.2+, Ba.sub.xSr.sub.1-xF.sub.2:Eu.sup.2+ (wherein 0≤x≤1), BaSrMgSi.sub.2O.sub.7:Eu.sup.2+, BaTiP.sub.2O.sub.7, (Ba,Ti).sub.2P.sub.2O.sub.7:Ti, Ba.sub.3WO.sub.6:U, BaY.sub.2F.sub.8:Er.sup.3+,Yb.sup.+, Be.sub.2SiO.sub.4:Mn.sup.2+, Bi.sub.4Ge.sub.3O.sub.12, CaAl.sub.2O.sub.4:Ce.sup.3+, CaLa.sub.4O.sub.7:Ce.sup.3+, CaAl.sub.2O.sub.4:Eu.sup.2+, CaAl.sub.2O.sub.4:Mn.sup.2+, CaAl.sub.4O.sub.7:Pb.sup.2+, Mn.sup.2+, CaAl.sub.2O.sub.4:Tb.sup.3+, Ca.sub.3Al.sub.2Si.sub.3O.sub.12:Ce.sup.3+, Ca.sub.3Al.sub.2Si.sub.3O.sub.12:Eu.sup.2+, Ca.sub.2B.sub.5O.sub.9Br:Eu.sup.2+, Ca.sub.2B.sub.5O.sub.9Cl:Eu.sup.2+, Ca.sub.2B.sub.5O.sub.9C:Pb.sup.2+, CaB.sub.2O.sub.4:Mn.sup.2+, Ca.sub.2B.sub.2O.sub.5:Mn.sup.2+, CaB.sub.2O.sub.4:Pb.sup.2+, CaB.sub.2P.sub.2O.sub.9:Eu.sup.2+, Ca.sub.5B.sub.2SiO.sub.10:Eu.sup.3+, Ca.sub.0.5Ba.sub.0.5Al.sub.12O.sub.19:Ce.sup.3+,Mn.sup.2+, Ca.sub.2Ba.sub.3(PO.sub.4).sub.3Cl:Eu.sup.2+, CaBr.sub.2:Eu.sup.2+ in SiO.sub.2, CaCl.sub.2):Eu.sup.2+ in SiO.sub.2, CaCl.sub.2:Eu.sup.2+,Mn.sup.2+ in SiO.sub.2, CaF.sub.2:Ce.sup.3+, CaF.sub.2:Ce.sup.3+,Mn.sup.2+, CaF.sub.2:Ce.sup.3+,Tb.sup.3+, CaF.sub.2:Eu.sup.2+, CaF.sub.2:Mn.sup.2+, CaF.sub.2:U, CaGa.sub.2O.sub.4:Mn.sup.2+, CaGa.sub.4O.sub.7:Mn.sup.2+, CaGa.sub.2S.sub.4:Ce.sup.3+, CaGa.sub.2S.sub.4:Eu.sup.2+, CaGa.sub.2S.sub.4:Mn.sup.2+, CaGa.sub.2S.sub.4:Pb.sup.2+, CaGeO.sub.3:Mn.sup.2+, CaI.sub.2:Eu.sup.2+ in SiO.sub.2, CaI.sub.2:Eu.sup.2+,Mn.sup.2+ in SiO.sub.2, CaLaBO.sub.4:Eu.sup.3+, CaLaB.sub.3O.sub.7:Ce.sup.3+,Mn.sup.2+, Ca.sub.2La.sub.2BO.sub.6.5:Pb.sup.2+, Ca.sub.2MgSi.sub.2O.sub.7, Ca.sub.2MgSi.sub.2O.sub.7:Ce.sup.3+, CaMgSi.sub.2O.sub.6:Eu.sup.2+, Ca.sub.3MgSi.sub.2O.sub.8:Eu.sup.2+, Ca.sub.2MgSi.sub.2O.sub.7:Eu.sup.2+, CaMgSi.sub.2O.sub.6:Eu.sup.2+,Mn.sup.2+, Ca.sub.2MgSi.sub.2O.sub.7:Eu.sup.2+,Mn.sup.2+, CaMoO.sub.4, CaMoO.sub.4:Eu.sup.3+, CaO:Bi.sup.3+, CaO:Cd.sup.2+, CaO:Cu.sup.+, CaO:Eu.sup.3+, CaO:Eu.sup.3+, Na.sup.+, CaO:Mn.sup.2+, CaO:Pb.sup.2+, CaO:Sb.sup.3+, CaO:Sm.sup.3+, CaO:Tb.sup.3+, CaO:Tl, CaO:Zn.sup.2+, Ca.sub.2P.sub.2O.sub.7:Ce.sup.3+, α-Ca.sub.3(PO.sub.4).sub.2:Ce.sup.3+, β-Ca.sub.3(PO.sub.4).sub.2:Ce.sup.3+, Ca.sub.5(PO.sub.4).sub.3Cl:Eu.sup.2+, Ca.sub.5(PO.sub.4).sub.3Cl:Mn.sup.2+, Ca.sub.5(PO.sub.4).sub.3Cl:Sb.sup.3+, Ca.sub.5(PO.sub.4).sub.3Cl:Sn.sup.2+, β-Ca.sub.3(PO.sub.4).sub.2:Eu.sup.2+,Mn.sup.2+, Ca.sub.5(PO.sub.4).sub.3F:Mn.sup.2+, Ca.sub.5(PO.sub.4).sub.3F:Sb.sup.3+, Ca.sub.5(PO.sub.4).sub.3F:Sn.sup.2+, α-Ca.sub.3(PO.sub.4).sub.2:Eu.sup.2+, β-Ca.sub.3(PO.sub.4).sub.2:Eu.sup.2+, Ca.sub.2P.sub.2O.sub.7:Eu.sup.2+, Ca.sub.2P.sub.2O.sub.7:Eu.sup.2+,Mn.sup.2+, CaP.sub.2O.sub.6:Mn.sup.2+, α-Ca.sub.3(PO.sub.4).sub.2:Pb.sup.2+, α-Ca.sub.3(PO.sub.4).sub.2:Sn.sup.2+, β-Ca.sub.3(PO.sub.4).sub.2:Sn.sup.2+, β-Ca.sub.2P.sub.2O.sub.7:Sn, Mn, α-Ca.sub.3(PO.sub.4).sub.2:Tr, CaS:Bi.sup.3+, CaS:Bi.sup.3+,Na, CaS:Ce.sup.3+, CaS:Eu.sup.2+, CaS:Cu+,Na+, CaS:La.sup.3+, CaS:Mn.sup.2+, CaSO.sub.4:Bi, CaSO.sub.4:Ce.sup.3+, CaSO.sub.4:Ce.sup.3+,Mn.sup.2+, CaSO.sub.4:Eu.sup.2+, CaSO.sub.4:Eu.sup.2+,Mn.sup.2+, CaSO.sub.4:Pb.sup.2+, CaS:Pb.sup.2+, CaS:Pb.sup.2+,Cl, CaS:Pb.sup.2+,Mn.sup.2+, CaS:Pr.sup.3+,Pb.sup.2+,Cl, CaS:Sb.sup.3+, CaS:Sb.sup.3+,Na, CaS:Sm.sup.3+, CaS:Sn.sup.2+, CaS:Sn.sup.2+,F, CaS:Tb.sup.3+, CaS:Tb.sup.3+,Cl, CaS:Y.sup.3+, CaS:Yb.sup.2+, CaS:Yb.sup.2+,Cl, CaSiO.sub.3:Ce.sup.3+, Ca.sub.3SiO.sub.4Cl.sub.2:Eu.sup.2+, Ca.sub.3SiO.sub.4Cl.sub.2:Pb.sup.2+, CaSiO.sub.3:Eu.sup.2+, CaSiO.sub.3:Mn.sup.2+,Pb, CaSiO.sub.3:Pb.sup.2+, CaSiO.sub.3:Pb.sup.2+,Mn.sup.2+, CaSiO.sub.3:Ti.sup.4+, CaSr.sub.2(PO.sub.4).sub.2:Bi.sup.3+, β-(Ca,Sr).sub.3(PO.sub.4).sub.2:Sn.sup.2+ Mn.sup.2+, CaTi.sub.0.9Al.sub.0.1O.sub.3:Bi.sup.3+, CaTiO.sub.3:Eu.sup.3+, CaTiO.sub.3:Pr.sup.3+, Ca.sub.5(VO.sub.4).sub.3C.sub.1, CaWO.sub.4, CaWO.sub.4: Pb.sup.2+, CaWO.sub.4:W, Ca.sub.3WO.sub.6:U, CaYAlO.sub.4:EU.sup.3+, CaYBO.sub.4:Bi.sup.3+, CaYBO.sub.4:Eu.sup.3+, CaYB.sub.0.8O.sub.3.7:Eu.sup.3+, CaY.sub.2ZrO.sub.6:Eu.sup.3+, (Ca,Zn,Mg).sub.3(PO.sub.4).sub.2:Sn, CeF.sub.3, (Ce,Mg)BaAl.sub.11O.sub.18:Ce, (Ce,Mg)SrAl.sub.11O.sub.18:Ce, CeMgAl.sub.11O.sub.19:Ce:Tb, Cd.sub.2B.sub.6O.sub.11:Mn.sup.2+, CdS:Ag.sup.+,Cr, CdS:In, CdS:In, CdS:In,Te, CdS:Te, CdWO.sub.4, CsF, CsI, CsI:Na.sup.+, CsI:Tl, (ErCl.sub.3).sub.0.25(BaI.sub.2).sub.0.75, GaN:Zn, Gd.sub.3Ga.sub.5O.sub.12:Cr.sup.3+, Gd.sub.3Ga.sub.5O.sub.12:Cr,Ce, GdNbO.sub.4:Bi.sup.3+, Gd.sub.2O.sub.2S:Eu.sup.3+, Gd.sub.2O.sub.2SPr.sup.3+, Gd.sub.2O.sub.2S:Pr,Ce, F, Gd.sub.2O.sub.2S:Tb.sup.3+, Gd.sub.2SiO.sub.5:Ce.sup.3+, KAl.sub.11O.sub.17:Tl+, KGa.sub.11O.sub.17:Mn.sup.2+, K.sub.2La.sub.2Ti.sub.3O.sub.10:Eu, KMgF.sub.3:Eu.sup.2+, KMgF.sub.3:Mn.sup.2+, K.sub.2SiF.sub.6:Mn.sup.4+, LaAl.sub.3B.sub.4O.sub.12:Eu.sup.3+, LaAlB.sub.2O.sub.6:Eu.sup.3+, LaAlO.sub.3:Eu.sup.3+, LaAlO.sub.3:Sm.sup.3+, LaAsO.sub.4:Eu.sup.3+, LaBr.sub.3:Ce.sup.3+, LaBO.sub.3:Eu.sup.3+, (La,Ce,Tb)PO.sub.4:Ce:Tb, LaCl.sub.3:Ce.sup.3+, La.sub.2O.sub.3:Bi.sup.3+, LaOBr:Tb.sup.3+, LaOBr:Tm.sup.3+, LaOCl:Bi.sup.3+, LaOCl:Eu.sup.3+, LaOF:Eu.sup.3+, La.sub.2O.sub.3:Eu.sup.3+, La.sub.2O.sub.3:Pr.sup.3+, La.sub.2O.sub.2S:Tb.sup.3+, LaPO.sub.4:Ce.sup.3+, LaPO.sub.4:Eu.sup.3+, LaSiO.sub.3Cl:Ce.sup.3+, LaSiO.sub.3Cl:Ce.sup.3+,Tb.sup.3+, LaVO.sub.4:Eu.sup.3+, La.sub.2W.sub.3O.sub.12:Eu.sup.3+, LiAIF.sub.4:Mn.sup.2+, LiAl.sub.5O.sub.8:Fe.sup.3+, LiAlO.sub.2:Fe.sup.3+, LiAlO.sub.2:Mn.sup.2+, LiAl.sub.5O.sub.8:Mn.sup.2+, Li.sub.2CaP.sub.2O.sub.7:Ce.sup.3+,Mn.sup.2+, LiCeBa.sub.4Si.sub.4O.sub.14:Mn.sup.2+, LiCeSrBa.sub.3Si.sub.4O.sub.14:Mn.sup.2+, LiInO.sub.2:Eu.sup.3+, LiInO.sub.2:Sm.sup.3+, LiLaO.sub.2:Eu.sup.3+, LuAlO.sub.3:Ce.sup.3+, (Lu,Gd).sub.2SiO.sub.5:Ce.sup.3+, Lu.sub.2SiO.sub.5:Ce.sup.3+, Lu.sub.2Si.sub.2O.sub.7:Ce.sup.3+, LuTaO.sub.4:Nb.sup.5+, Lu.sub.1-XYXAlO.sub.3:Ce.sup.3+ (wherein 0≤x≤1), MgAl.sub.2O.sub.4:Mn.sup.2+, MgSrAl.sub.10O.sub.17:Ce, MgB.sub.2O.sub.4:Mn.sup.2+, MgBa.sub.2(PO.sub.4).sub.2:Sn.sup.2+, MgBa.sub.2(PO.sub.4).sub.2:U, MgBaP.sub.2O.sub.7:Eu.sup.2+, MgBaP.sub.2O.sub.7:Eu.sup.2+,Mn.sup.2+, MgBa.sub.3Si.sub.2O.sub.8:Eu.sup.2+, MgBa(SO.sub.4).sub.2:Eu.sup.2+, Mg.sub.3Ca.sub.3(PO.sub.4).sub.4:Eu.sup.2+, MgCaP.sub.2O.sub.7:Mn.sup.2+, Mg.sub.2Ca(SO.sub.4).sub.3:Eu.sup.2+, Mg.sub.2Ca(SO.sub.4).sub.3:Eu.sup.2+,Mn.sup.2, MgCeAl.sub.11O.sub.19:Tb.sup.3+, Mg.sub.4(F)GeO.sub.6:Mn.sup.2+, Mg.sub.4(F)(Ge,Sn)O.sub.6:Mn.sup.2+, MgF.sub.2:Mn.sup.2+, MgGa.sub.2O.sub.4:Mn.sup.2+, Mg.sub.8Ge.sub.2O.sub.11F.sub.2:Mn.sup.4+, MgS:Eu.sup.2+, MgSiO.sub.3:Mn.sup.2+, Mg.sub.2SiO.sub.4:Mn.sup.2+, Mg.sub.3SiO.sub.3F.sub.4:Ti.sup.4+, MgSO.sub.4:Eu.sup.2+, MgSO.sub.4:Pb.sup.2+, (Mg,Sr)Ba.sub.2Si.sub.2O.sub.7:Eu.sup.2+, MgSrP.sub.2O.sub.7:Eu.sup.2+, MgSr.sub.5(PO.sub.4).sub.4:Sn.sup.2+, MgSr.sub.3Si.sub.2O.sub.8:Eu.sup.2+,Mn.sup.2+, Mg.sub.2Sr(SO.sub.4).sub.3:Eu.sup.2+, Mg.sub.2TiO.sub.4:Mn.sup.4+, MgWO.sub.4, MgYBO.sub.4:Eu.sup.3+, Na.sub.3Ce(PO.sub.4).sub.2:Tb.sup.3+, NaI:Tl, Na.sub.1.23K.sub.0.42Eu.sub.0.12TiSi.sub.4O.sub.11:Eu.sup.3+, Na.sub.1.23K.sub.0.42Eu.sub.0.12TiSi.sub.5O.sub.13.xH.sub.2O:EU.sup.3+, Na.sub.1.29K.sub.0.46Er.sub.0.08TiSi.sub.4O.sub.11:Eu.sup.3+, Na.sub.2Mg.sub.3Al.sub.2Si.sub.2O.sub.10:Tb, Na(Mg.sub.2-XMn.sub.X)LiSi.sub.4O.sub.10F.sub.2:Mn (wherein 0≤x≤2), NaYF.sub.4:Er.sup.3+, Yb.sup.3+, NaYO.sub.2:Eu.sup.3+, P46(70%)+P47 (30%), SrAl.sub.12O.sub.19:Ce.sup.3+, Mn.sup.2+, SrAl.sub.2O.sub.4:Eu.sup.2+, SrAl.sub.4O.sub.7:Eu.sup.3+, SrAl.sub.12O.sub.19:Eu.sup.2+, SrAl.sub.2S.sub.4:Eu.sup.2+, Sr.sub.2B.sub.5O.sub.9Cl:Eu.sup.2+, SrB.sub.4O.sub.7:Eu.sup.2+ (F,Cl, Br), SrB.sub.4O.sub.7:Pb.sup.2+, SrB.sub.4O.sub.7:Pb.sup.2+, Mn.sup.2+, SrB.sub.8O.sub.13:Sm.sup.2+, Sr.sub.xBa.sub.yCl.sub.zAl.sub.2O.sub.4-z/2: Mn.sup.2+, Ce.sup.3+, SrBaSiO.sub.4:Eu.sup.2+, Sr(Cl,Br,I).sub.2:Eu.sup.2+ in SiO.sub.2, SrCl.sub.2:Eu.sup.2+ in SiO.sub.2, Sr.sub.5Cl(PO.sub.4).sub.3:Eu, Sr.sub.wF.sub.xB.sub.4O.sub.6.5:Eu.sup.2+, Sr.sub.wF.sub.xB.sub.yO.sub.z:E.sup.2,Sm.sup.2+, SrF.sub.2:Eu.sup.2+, SrGa.sub.12O.sub.19:Mn.sup.2+, SrGa.sub.2S.sub.4:Ce.sup.3+, SrGa.sub.2S.sub.4:Eu.sup.2+, SrGa.sub.2S.sub.4:Pb.sup.2+, SrIn.sub.2O.sub.4:Pr.sup.3+, Al.sup.3+, (Sr,Mg).sub.3(PO.sub.4).sub.2:Sn, SrMgSi.sub.2O.sub.6:Eu.sup.2+, Sr.sub.2MgSi.sub.2O.sub.7:Eu.sup.2+, Sr.sub.3MgSi.sub.2O.sub.8:Eu.sup.2+, SrMoO.sub.4:U, SrO..sub.3B.sub.2O.sub.3:Eu.sup.2+,Cl, β-SrO..sub.3B.sub.2O.sub.3:Pb.sup.2+, β-SrO..sub.3B.sub.2O.sub.3:Pb.sup.2+,Mn.sup.2+, α-SrO..sub.3B.sub.2O.sub.3:Sm.sup.2+, Sr.sub.6P.sub.5BO.sub.20:Eu, Sr.sub.5(P.sub.4).sub.3GCl:Eu.sup.2+, Sr.sub.5(PO.sub.4).sub.3GC:Eu.sup.2+,Pr.sup.3+, Sr.sub.5(PO.sub.4).sub.3GC:Mn.sup.2+, Sr.sub.5(PO.sub.4).sub.3GC:Sb.sup.3+, Sr.sub.2P.sub.2O.sub.7:Eu.sup.2+, R.sup.3—Sr.sub.3(PO.sub.4).sub.2:Eu.sup.2+, Sr.sub.5(PO.sub.4).sub.3F:Mn.sup.2+, Sr.sub.5(PO.sub.4).sub.3F:Sb.sup.3+, Sr.sub.5(PO.sub.4).sub.3F:Sb.sup.3+,Mn.sup.2+, Sr.sub.5(PO.sub.4).sub.3F:Sn.sup.2+, Sr.sub.2P.sub.2O.sub.7:Sn.sup.2+, β-Sr.sub.3(PO.sub.4).sub.2:Sn.sup.2+, β-Sr.sub.3(PO.sub.4).sub.2:Sn.sup.2+,Mn.sup.2+ (Al), SrS:Ce.sup.3+, SrS:Eu.sup.2+, SrS:Mn.sup.2+, SrS:Cu+,Na, SrSO.sub.4:Bi, SrSO.sub.4:Ce.sup.3+, SrSO.sub.4:Eu.sup.2+, SrSO.sub.4:Eu.sup.2+,Mn.sup.2+, Sr.sub.5Si.sub.4O.sub.10Cl.sub.6:Eu.sup.2+, Sr.sub.2SiO.sub.4:Eu.sup.2+, SrTiO.sub.3:Pr.sup.3+, SrTiO.sub.3:Pr.sup.3+,Al.sup.3+, Sr.sub.3WO.sub.6:U, SrY.sub.2O.sub.3:Eu.sup.3+, ThO.sub.2:Eu.sup.3+, ThO.sub.2:Pr.sup.3+, ThO.sub.2:Tb.sup.3+, YAl.sub.3B.sub.4O.sub.12:Bi.sup.3+, YAl.sub.3B.sub.4O.sub.12:Ce.sup.3+, YAl.sub.3B.sub.4O.sub.12:Ce.sup.3+,Mn, YAl.sub.3B.sub.4O.sub.12:Ce.sup.3+,Tb.sup.3+, YAl.sub.3B.sub.4O.sub.12:Eu.sup.3+, YAl.sub.3B.sub.4O.sub.12:Eu.sup.3+,Cr.sup.3+, YAl.sub.3B.sub.4O.sub.12:Th.sup.4+,Ce.sup.3+,Mn.sup.2+, YAlO.sub.3:Ce.sup.3+, Y.sub.3Al.sub.5O.sub.12:Ce.sup.3+, Y.sub.3Al.sub.5O.sub.12:Cr.sup.3+, YAlO.sub.3:Eu.sup.3+, Y.sub.3AlO.sub.2:Eu.sup.3r, Y.sub.4Al.sub.2O.sub.9:Eu.sup.3+, Y.sub.3Al.sub.5O.sub.12:Mn.sup.4+, YAlO.sub.3:Sm.sup.3+, YAlO.sub.3:Tb.sup.3+, Y.sub.3Al.sub.5O.sub.12:Tb.sup.3+, YAsO.sub.4:Eu.sup.3+, YBO.sub.3:Ce.sup.3+, YBO.sub.3:Eu.sup.3+, YF.sub.3:Er.sup.3+,Yb.sup.3+, YF.sub.3:Mn.sup.2+, YF.sub.3:Mn.sup.2+,Th.sup.4+, YF.sub.3:Tm.sup.3+,Yb.sup.3+, (Y,Gd)BO.sub.3:Eu, (Y,Gd)BO.sub.3:Tb, (Y,Gd).sub.2O.sub.3:Eu.sup.3+, Y.sub.1.34Gd.sub.0.60O.sub.3(Eu,Pr), Y.sub.2O.sub.3:Bi.sup.3+, YOBr:Eu.sup.3+, Y.sub.2O.sub.3:Ce, Y.sub.2O.sub.3:Er.sup.3+, Y.sub.2O.sub.3:Eu.sup.3+ (YOE), Y.sub.2O.sub.3:Ce.sup.3+,Tb.sup.3+, YOCl:Ce.sup.3+, YOCl:Eu.sup.3+, YOF:Eu.sup.3+, YOF:Tb.sup.3+, Y.sub.2O.sub.3:Ho.sup.3+, Y.sub.2O.sub.2S:Eu.sup.3+, Y.sub.2O.sub.2S:Pr.sup.3+, Y.sub.2O.sub.2S:Tb.sup.3+, Y.sub.2O.sub.3:Tb.sup.3+, YPO.sub.4:Ce.sup.3+, YPO.sub.4:Ce.sup.3+,Tb.sup.3+, YPO.sub.4:Eu.sup.3+, YPO.sub.4:Mn.sup.2+,Th.sup.4+, YPO.sub.4:V.sup.5+, Y(P,V).sub.04:Eu, Y.sub.2SiO.sub.5:Ce.sup.3+, YTaO.sub.4, YTaO.sub.4:Nb.sup.5+, YVO.sub.4:Dy.sup.3+, YVO.sub.4:Eu.sup.3+, ZnAl.sub.2O.sub.4:Mn.sup.2+, ZnB.sub.2O.sub.4:Mn.sup.2+, ZnBa.sub.2S.sub.3:Mn.sup.2+, (Zn,Be).sub.2SiO.sub.4:Mn.sup.2+, Zn.sub.0.4Cd.sub.0.6S:Ag, Zn.sub.0.6Cd.sub.0.4S:Ag, (Zn,Cd)S:Ag,Cl, (Zn,Cd)S:Cu, ZnF.sub.2:Mn.sup.2+, ZnGa.sub.2O.sub.4, ZnGa.sub.2O.sub.4:Mn.sup.2+, ZnGa.sub.2S.sub.4:Mn.sup.2+, Zn.sub.2GeO.sub.4:Mn.sup.2+, (Zn,Mg)F.sub.2:Mn.sup.2+, ZnMg.sub.2(PO.sub.4).sub.2:Mn.sup.2+, (Zn,Mg).sub.3(PO.sub.4).sub.2:Mn.sup.2+, ZnO:Al.sup.3+,Ga.sup.3+, ZnO:Bi.sup.3+ ZnO:Ga.sup.3+, ZnO:Ga, ZnO—CdO:Ga, ZnO:S, ZnO:Se, ZnO:Zn, ZnS:Ag+,Cl.sup.−, ZnS:Ag,Cu,Cl, ZnS:Ag,Ni, ZnS:Au,In, ZnS—CdS (25-75), ZnS—CdS (50-50), ZnS—CdS (75-25), ZnS—CdS:Ag,Br,Ni, ZnS—CdS:Ag+,Cl, ZnS—CdS:Cu,Br, ZnS—CdS:Cu,I, ZnS:Cl.sup.−, ZnS:Eu.sup.2+, ZnS:Cu, ZnS:Cu.sup.+,Al.sup.3+, ZnS:Cu+,Cl.sup.−, ZnS:Cu,Sn, ZnS:Eu.sup.2+, ZnS:Mn.sup.2+, ZnS:Mn,Cu, ZnS:Mn.sup.2+,Te.sup.2+, ZnS:P, ZnS:P.sup.3−,Cl.sup.−, ZnS:Pb.sup.2+, ZnS:Pb.sup.2+,Cl.sup.−, ZnS:Pb,Cu, Zn.sub.3(PO.sub.4).sub.2:Mn.sup.2+, Zn.sub.2SiO.sub.4:Mn.sup.2+, Zn.sub.2SiO.sub.4:Mn.sup.2+,As.sup.5+, Zn.sub.2SiO.sub.4:Mn,Sb.sub.2O.sub.2, Zn.sub.2SiO.sub.4:Mn.sup.2+,P, Zn.sub.2SiO.sub.4:Ti.sup.4+, ZnS:Sn.sup.2+, ZnS:Sn,Ag, ZnS:Sn.sup.2+,Li+, ZnS:Te,Mn, ZnS—ZnTe:Mn.sup.2+, ZnSe:Cu.sup.+,Cl and/or ZnWO.sub.4.

(119) In a preferred embodiment of the present invention the dispersion contains a crosslinkable material and at least one phosphor, more preferably one, two or three or more phosphors in combination.

(120) For the purpose of the present application, the type of semiconductor nanoparticle converter is not particularly limited. Such converters may be semiconductor nanoparticles (quantum materials) or semiconductor nanoparticles (quantum materials) on the surface of non-activated crystalline materials as known from WO 2017/041875 A1.

(121) In a preferred embodiment of the present invention the dispersion contains a crosslinkable material and at least one semiconductor nanoparticle converter, more preferably two, three or more semiconductor nanoparticle converters in combination.

(122) In a particularly preferred embodiment of the present invention the dispersion contains a crosslinkable material and at least one phosphor and at least one semiconductor nanoparticle converter in combination.

(123) Wavelength Converting Component

(124) The present invention provides in a first embodiment a wavelength converting component which is obtainable or obtained by the manufacturing method as described hereinabove.

(125) The matrix material in the wavelength converting component shows particular physical features describing its semi-ceramic state such as the following features (1) to (6): (1) The matrix material has a hardness according to Shore-D (Shore-D hardness) of ≥75. (2) The matrix material has a thermal conductivity of ≥0.3 W/(m.Math.K) at 25° C. Preferably, the thermal conductivity of the matrix material is ≤5.0 W/(m.Math.K), more preferably ≤3.0 W/(m.Math.K), at 25° C. (3) The matrix material has a density of ≥1.16 g/cm.sup.3, preferably of ≥1.21 g/cm.sup.3, at 25° C. Preferably, the density of the matrix material is ≤2.50 g/cm.sup.3, more preferably ≤2.20 g/cm.sup.3, at 25° C. (4) The matrix material has a coefficient of thermal expansion (CTE) of ≤150 ppm/K in a temperature range from 25 to 80° C. Preferably, the CTE of the matrix material is ≥10 ppm/K, more preferably ≥20 ppm/K, in a temperature range from 25 to 80° C. (5) The matrix material is characterized by the absence of Si—H groups as analyzed by infrared (IR) spectroscopy, which means that there are no Si—H vibration bands at 2050 to 2250 cm.sup.−1 in the IR spectrum. (6) The matrix material shows a weight loss of ≤0.5 weight-%, upon heating from 25 to 350° C. under air atmosphere.

(126) The physical features (1) to (6) are obtained by the measurement methods as described below in the examples.

(127) The physical features (1) to (6), either alone or in any combination, may characterize the wavelength converting component and describe the semi-ceramic state of the matrix material resulting from a high degree of crosslinking due to high curing temperatures.

(128) Particularly preferred physical features characterizing the semi-ceramic state of the matrix material are: (3) a density of ≥1.16 and ≤2.50 g/cm.sup.3, most preferably of ≥1.21 and ≤2.20 g/cm.sup.3, at 25° C. (4) a coefficient of thermal expansion (CTE) of ≤150 and ≥10 ppm/K, most preferably of ≤150 and ≥20 ppm/K, in a temperature range from 25 to 80° C. (5) the absence of Si—H groups as analyzed by infrared (IR) spectroscopy, which means that there are no Si—H vibration bands at 2050 to 2250 cm.sup.−1 in the IR spectrum.

(129) It is preferred that the wavelength converting components of the first embodiment is further characterized by one or more of the physical features (1) to (6) shown above.

(130) In a second embodiment of the present invention there is provided a wavelength converting component containing at least one wavelength converting material embedded in a matrix material, wherein the matrix material contains Si—N bonds and wherein the matrix material has a density of ≥1.16 g/cm.sup.3, preferably of ≥1.21 g/cm.sup.3, at 25° C. It is preferred that the density of the matrix material is ≤2.50 g/cm.sup.3, more preferably ≤2.20 g/cm.sup.3, at 25° C.

(131) It is preferred that the wavelength converting components of the second embodiment is further characterized by one or more of the physical features (1), (2) and (4) to (6) shown above.

(132) In a third embodiment of the present invention there is provided a wavelength converting component containing at least one wavelength converting material embedded in a matrix material, wherein the matrix material contains Si—N bonds and wherein the matrix material has a coefficient of thermal expansion of ≤150 ppm/K in a temperature range from 25 to 80° C. It is preferred that the CTE of the matrix material is ≥10 ppm/K, more preferably ≥20 ppm/K, in a temperature range from 25 to 80° C.

(133) It is preferred that the wavelength converting components of the third embodiment is further characterized by one or more of the physical features (1) to (3), (5) and (6) shown above.

(134) Light Source

(135) There is further provided a light source comprising a primary light source and a wavelength converting component according to the present invention.

(136) Preferred primary light sources are semiconductor light emitting sources such as semiconductor light emitting diodes (LED chips) or semiconductor laser diodes (LD chips).

(137) Preferred LED chips comprise a luminescent indium aluminum gallium nitride, in particular of the formula In.sub.iGa.sub.jAl.sub.kN, where 0≤i, 0≤j, 0≤k, and i+j+k=1.In a further preferred embodiment, the LED chip is a luminescent arrangement based on ZnO, TCO (transparent conducting oxide), ZnSe or SiC.

(138) It is preferred that the light source of the present invention is a high power LED, an ultra-high power LED or a laser LED.

(139) The light source of the present invention preferably emits white light or light having a certain colour point (colour-on-demand principle). The colour-on-demand concept is taken to mean the production of light having a certain colour point using a pc-LED (=phosphor-converted LED) using one or more phosphors.

(140) In a preferred embodiment the wavelength converting component is either arranged directly on the primary light source or alternatively arranged remote therefrom, depending on the respective type of application (the latter arrangement also includes “remote phosphor technology”) (FIG. 4). The advantages of remote phosphor technology are known to the person skilled in the art and are revealed, for example, by the following publication: Japanese J. of Appl. Phys. Vol. 44, No. 21 (2005), L649-L651.

(141) The wavelength converting component can be placed either on the LED wafer prior to dicing as shown in FIG. 6 or on the singularized LED chip as shown in FIG. 7.

(142) The optical coupling between the primary light source and the wavelength converting component can also be achieved by a light-conducting arrangement. This makes it possible for the primary light source to be installed at a central location and to be optically coupled to the converter by means of light-conducting devices, such as, for example, optical fibers. In this way, it is possible to achieve lamps adapted to the lighting wishes which merely consist of one or more types of wavelength converting material, which can be arranged to form a light screen, and an optical waveguide, which is coupled to the primary light source. In this way, it is possible to place a strong primary light source at a location which is favourable for electrical installation and to install lamps comprising wavelength converting material which are coupled to the optical waveguides at any desired locations without further electrical cabling, but instead only by laying optical wave-guides.

(143) It is preferred that the light source according to the present invention is used for projectors (image projectors) or automotive lighting.

(144) Lighting Unit

(145) There is further provided a lighting unit, in particular for projectors (image projectors) or automotive lighting, wherein the lighting unit comprises at least one of the inventive light sources.

(146) For light conversion in laser LEDs, e.g. in the automotive environment, the wavelength converting component in the lighting unit can be used in transmission mode (FIG. 2) or in refection mode (FIG. 3).

(147) For light conversion in laser LEDs, e.g. in projectors, the wavelength converting component in the lighting unit can be used on a colour wheel, as for example described in “https://www.christiedigital.com/en-us/display-technology/laser-projection/laser-phosphor-projection”.

(148) Use

(149) The wavelength converting component of the present invention may be used for the conversion of blue, violet and/or UV light from a primary light source into light with a longer wavelength. It is preferred that the primary light source is a semiconductor light emitting diode (LED chip) or a semiconductor laser diode (LD chip).

(150) The present invention is further illustrated by the examples following hereinafter which shall in no way be construed as limiting. The skilled person will acknowledge that various modifications, additions and alternations may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims.

EXAMPLES

(151) General Procedures

(152) The wavelength converting material is made by mixing organopolysilazanes, organopolysiloxazanes or PHPS and wavelength converting particles and heating the mixture over two stages to temperatures of >250 to ≤500° C. At temperatures between 250 and 500° C. the silazane and/or siloxazane polymer crosslinks to a very dense polymer. This polymer is herein called “semi-ceramic material”. It shows no discolouration at temperatures of up to 300° C. and has good barrier properties due to the high crosslinking degree.

(153) A major advantage of this approach is the liquid precursor dispersion, which can be easily poured into various molds and then cured to form a solid part. By this method, parts of various shapes, for example plain platelets or lens-like parts can be prepared (FIG. 5).

(154) Alternatively, it is possible to apply the liquid formulation on a LED wafer or a LD wafer by spin-coating or slot-die coating (wafer level coating) (FIG. 6). There is no need for a very small sized wavelength converting material, all usual particle sizes of typically ≥3 to ≤30 μm are possible. After attach-ing the wavelength converting component onto a high power LED chip, ultra-high power LED chip or LD chip, the light source can be run at very high current. Then the wavelength converting component reaches temperatures of >200° C. without any yellowing. There is no change in colour point observable during a long-time reliability test. An additional advantage is the good barrier property of the semi-ceramic material against water and moisture permeation. It protects sensitive phosphor materials against degradation under high humidity conditions. The improved thermal conductivity of the highly crosslinked material is an additional advantage.

(155) The heat generated by the Stokes shift in the phosphor particles is easier dissipated.

(156) Characterization of the Wavelength Converting Component

(157) Material Properties

(158) To demonstrate the change of material properties by heat induced crosslinking, various physical parameters were analyzed after 120° C. cure and after temperature treatment up to 350° C. The material used was an organopolysiloxazane having the following structure:
—[Si(H)CH.sub.3—NH].sub.a—[Si(CH.sub.3).sub.2—NH].sub.b—[Si(CH.sub.3).sub.2—O].sub.c—
wherein a:b:c=60:20:20. The material was cured at a temperature of 120° C. for 16 h on a hot plate in ambient atmosphere. After curing the material was solid and was then subsequently heated to 150° C., 200° C., 250° C., 300° C. and 350° C., respectively, each temperature for 24 h in an oven at air atmosphere.

(159) Coefficient of Thermal Expansion (CTE)

(160) The semi-ceramic material is characterized by an average CTE of <150 ppm/K in a temperature range of 25° C.-80° C. and of <180 ppm/K in a temperature range of 80° C.-150° C. (see FIG. 8).

(161) Hardness

(162) The semi-ceramic material has a Shore-D hardness at 25° C. of >75 (see Table 1).

(163) TABLE-US-00001 TABLE 1 Dependence of the Shore D hardness on curing conditions. Curing conditions 120° C. +150° C. +200° C. +250° C. +300° C. +350° C. for 24 h for 24 h for 24 h for 24 h for 24 h for 24 h Shore D Hardness 15 35 60 75 >75 >75

(164) Thermal Conductivity

(165) The semi-ceramic material has a thermal conductivity of >0.3 W/(m*K) (see Table 2).

(166) TABLE-US-00002 TABLE 2 Dependence of thermal conductivity on curing conditions. Curing conditions 120° C. +150° C. +200° C. +250° C. +300° C. +350° C. for 24 h for 24 h for 24 h for 24 h for 24 h for 24 h Thermal conductivity 0.18 0.20 0.22 0.26 >0.3 >0.3 [W/(m*K)]

(167) Density

(168) The semi-ceramic material has a density of ≥1.16 g/cm.sup.3 (FIG. 9). The density was measured using a He Pycnometry Tool: Pycnometer AccuPyc™ 1330 Micrometrics™, Model 133/34010/00 according to method DIN 66137-2: Determination of solid state density, Part 2 Gaspycnometry.

(169) Presence of Organic Groups

(170) The semi-ceramic material still contains organic groups (FIG. 10). In FIG. 10 the signal of the Si—CH.sub.3 group vibration at 1250 to 1260 cm.sup.−1 remains unchanged.

(171) Absence of Si—H Groups

(172) The semi-ceramic material is characterized by the absence of silicon-hydrogen groups (see FIG. 10). In FIG. 10 the signal of the Si—H group vibration at 2050 to 2250 cm.sup.−1 disappears at T>250° C.

(173) Thermogravimetric Analysis (TGA)

(174) The semi-ceramic material shows a weight loss analyzed by TGA in air atmosphere of <0.5 weight-% after heating up to 350° C. (see FIG. 11).

(175) Measurement Methods

(176) Molecular weights of polymers were determined by GPC against a polystyrene standard. As eluent a mixture of tetrahydrofuran and 1.45 weight-% (relative to the total weight of the eluent) hexamethyldisilazane was used. Columns were Shodex KS-804 and 2×KS-802 and KS-801. The detector was an Agilent 1260 refractive index detector.

(177) Viscosity was determined using a Brookfield Rheometer R/S plus with a Brookfield cone-type spindle RC3-50-1 at a rotation speed of 3 rpm and a temperature of 25° C.

(178) The coefficient of thermal expansion (CTE) was measured using a Mettler-Toledo TMA/SDTA 1 System. Parts of a column-like shape with a diameter of 6 mm and a height of 6 mm were prepared and cured at the temperatures and times shown in FIG. 8. The CTE was measured at a heating rate of 2.5 K/min and the slope of the specimens height vs. temperature was evaluated in a temperature range from 25 to 80° C. and from 80 to 150° C.

(179) The Shore-D hardness was measured using a Elcometer 3120 Shore Durometer. A film of 1 mm thickness was prepared and cured at the conditions shown in Table 1.

(180) Thermal conductivity was measured with a Netzsch LFA 457 MicroFlash Laser Flash Apparatus. A part with a disc-like shape of 12 mm diameter and a height of 2 mm was prepared and cured at the conditions shown in Table 2.

(181) A film of 1 mm thickness was prepared and cured at the conditions shown in FIG. 9. The cured film was grinded to powder and the density was measured. The density was measured using a He Pycnometry Tool: Pycnometer AccuPyc™ 1330 Micrometrics™, Model 133/34010/00 according to method DIN 66137-2: Determination of solid state density, Part 2 Gaspycnometry.

(182) The presence of organic groups was measured by FT-IR spectroscopy using a Perkin-Elmer Frontier FT-IR Spectrometer in ATR mode. A 150 μm film was coated on a glass plate, cured at the temperatures shown in FIG. 10 and the FT-TR spectrum was measured in ATR mode.

(183) The absence of Si—H groups was measured by FT-IR spectroscopy using a Perkin-Elmer Frontier FT-IR Spectrometer in ATR mode. A 150 μm film was coated on a glass plate, cured at the temperatures shown in FIG. 10 and the FT-TR spectrum was measured in ATR mode. Si—H groups are absent, if there are no signals of the Si—H group vibration at 2050 to 2250 cm.sup.−1 in the IR spectrum.

(184) The thermogravimetric analysis (TGA) was done using a Mettler-Toledo TGA-2 Thermogravimetric Analyzer. A film of 0.5 mm thickness was prepared and cured at the conditions shown in FIG. 11. The cured film was grinded to powder and the TGA was measured at a heating rate of 10 K/min under air atmosphere

(185) The emission spectra and the colour point of the coated LEDs were measured using an Instrument System Spectrometer CAS 140CT in combination with an Instrument System Integration sphere ISP 150.

(186) The angular radiation intensity of the coated LEDs were measured using an Instrument System Spectrometer CAS 140CT in combination with an Instrument System Goniophotometer LEDGON.

(187) Preparation

(188) Table 3 shows the composition of the dispersions and curing conditions used for Examples 1 to 11.

(189) TABLE-US-00003 TABLE 3 Examples 1 to11. Ratio Curing Curing Ex. Precursor Phosphor Precursor:Phosphor Support Cat. temperature atmosphere 1 Material A YAG* 1:2.5 PTFE plate AlPh.sub.3  50 + 325° C. Air 2 Material A YAG* 1:2.5 PTFE plate — 150° C. Air 3 Material A YAG* + OGA** 1:1.7:0.8 PTFE plate — 150 + 325° C. Air 4 Material B YAG* + OGA** 1:1.7:0.8 PTFE plate — 150 + 325° C. Air 5 Material B YAG* 1:2.5 PTFE mold AlPh.sub.3  50 + 325° C. Air 6 PHPS YAG* 1:2.5 PTFE mold — 150 + 350° C. Air 7 PHPS YAG* 1:2.5 Glass plate — 150 + 350° C. Air 8 PHPS Thiogallate*** 1:2.5 Glass plate — 150 + 350° C. Air 9 Material B YAG* 1:2.5 Glass plate — 150 + 325° C. Air 10 Material A Thiogallate*** 1:2.5 Glass plate — 150 + 325° C. Air 11 Material A Thiogallate*** 1:2.5 PTFE plate AlPh.sub.3  50 + 325° C. Air *YAG = Isiphor ® YYG 545 200, available from Merck KGaA. **OGA = Isiphor ® OGA 600 500, available from Merck KGaA. ***Thiogallate = BUVG01 (Calcium Strontium Gallium Sulfoselenide doped with Europium), available from PHOSPHORTECH CORPORATION Atlanta/USA

(190) Material A is an organopolysilazane made of Cl—Si(H)CH.sub.3—Cl and Cl—Si(CH.sub.3).sub.2—Cl in a ratio of 1:1 and ammonia with an average molecular weight of 4,500 g/mol determined by GPC. This material is available from Merck KGaA under the tradename Durazane 1050.

(191) Material B is an organopolysiloxazane having an average molecular weight of 4,750 g/mol (determined by GPC) which was prepared according to the following procedure:

(192) A 4 l pressure vessel was charged with 1500 g of liquid ammonia at 0° C. and set under a pressure between 3 bar and 5 bar. A mixture of 442 g dichloromethylsilane and 384 g 1,3-dichlorotetramethyldisiloxane was slowly added over a period of 3 h. After stirring the resulting reaction mixture for additional 3 h the stirrer was stopped and the lower phase was isolated and evaporated to remove dissolved ammonia. After filtration 429 g of a colourless viscous oil remained.

(193) 100 g of the obtained colourless viscous oil was dissolved in 100 g 1,4-dioxane and cooled to 0° C. 100 mg KH was added and the reaction solution was stirred for 4h until gas formation stopped. 300 mg chlorotrimethylsilane and 250 g xylene were added and the temperature was raised to room temperature. The turbid solution was filtrated and the resulting clear solution was reduced to dryness at a temperature of 50° C. under a vacuum of ≤20 mbar to obtain 95 g of a colorless highly viscous oil.

Example 1

(194) A mixture of 10 g organopolysilazane Material A, 0.05 g triphenylaluminum (AlPh.sub.3), 1.5 g heptane and 25 g YAG phosphor was coated on a PTFE plate with a plain surface at a film thickness of 100 μm. The material was cured for 16 h under air atmosphere at a temperature of 50° C. The cured film was then removed from the PTFE support and a 1 mm×1 mm piece having a recess at one edge to fit on a LED chip (as shown in FIG. 7) was cut. The piece was then cured for additional 16 h under air atmosphere at a temperature of 325° C.

Example 2

(195) A mixture of 10 g organopolysilazane Material A, 1.5 g heptane and 25 g of YAG phosphor was coated on a PTFE plate with a plain surface at a film thickness of 100 μm. The material was cured for 16 h under air atmosphere at a temperature of 150° C. The cured film was then removed from the PTFE support and a 1 mm×1 mm piece having a recess at one edge to fit on a LED chip (as shown in FIG. 7) was cut.

Example 3

(196) A mixture of 10 g organopolysilazane Material A, 1.5 g Heptane, 17 g YAG Phosphor and 8 g OGA Phosphor was coated on a PTFE plate with a plain surface at a film thickness of 100 μm. The material was cured for 16 h under air atmosphere at a temperature of 150° C. The cured film was then removed from the PTFE support and a 1 mm×1 mm piece having a recess at one edge to fit on a LED chip (as shown in FIG. 7) was cut. The piece was then cured for additional 16 h under air atmosphere at a temperature of 325° C.

Example 4

(197) Example 4 is identical to Example 3, except that Material B was used.

Example 5

(198) A mixture of 10 g organopolysiloxazane Material B, 0.05 g triphenylaluminum (AlPh.sub.3), 1.5 g heptane and 25 g YAG phosphor was coated into a cavity of a PTFE mold. The cavity had an inverse lens shape as shown in FIG. 14. The material was cured for 16 h under air atmosphere at a temperature of 50° C. The cured material was then removed from the PTFE mold and the piece was cured for additional 16 h under air atmosphere at a temperature of 325° C.

Example 6

(199) A mixture of 20 g PHPS (50% in Di-n-butyl ether) and 25 g YAG phosphor was coated into a cavity of a PTFE mold. The cavity had an inverse lens shape as shown in FIG. 14. The material was cured for 16 h under air atmosphere at a temperature of 150° C. The cured material was then removed from the PTFE mold and the piece was cured for additional 16 h under air atmosphere at a temperature of 350° C.

Example 7

(200) A mixture of 20 g PHPS (50% in Di-n-butyl ether) and 25 g of YAG phosphor was coated on a plain glass plate (the glass plate was cut of glass type “Dünnglas AF 32 eco”, diameter 7 mm, thickness 0.3 μm, available from Schott AG Landshut/Germany) of the shape as shown in FIG. 15 at a film thickness of 150 μm. The material was cured for 16 h under air atmosphere at a temperature of 150° C. and additional 16 h under air atmosphere at a temperature of 350° C.

Example 8

(201) Example 8 was similar to Example 7, except that a thiogallate phosphor was used.

Example 9

(202) A mixture of 10 g organopolysiloxazane Material B 1.5 g heptane and 25 g YAG phosphor was coated on a plain glass plate of the shape as shown in FIG. 15 at a film thickness of 150 μm. The material was cured for 16 h under air atmosphere at a temperature of 150° C. and additional 16 h under air atmosphere at a temperature of 325° C.

Example 10

(203) A mixture of 10 g organopolysilazane Material A, 1.5 g heptane and 25 g of thiogallate phosphor was coated on a plain glass plate of the shape as shown in FIG. 15 at a film thickness of 150 μm. The material was cured for 16 h under air atmosphere at a temperature of 150° C. and additional 16 h under air atmosphere at a temperature of 325° C.

Example 11

(204) A mixture of 10 g organopolysilazane Material A, 0.05 g triphenylaluminum (AlPh.sub.3), 1.5 g heptane and 25 g thiogallate phosphor was coated on a PTFE plate with a plain surface at a film thickness of 100 μm. The material was cured for 16 h under air atmosphere at a temperature of 50° C. The cured film was then removed from the PTFE support and a 1 mm×1 mm piece having a recess at one edge to fit on a LED chip (as shown in FIG. 7) was cut. The piece was then cured for 16 h under air atmosphere at a temperature of 325° C.

(205) LED Devices

(206) To show its usefulness for LED devices, the wavelength converting components prepared in the examples above were tested in LED packages. The platelets were attached on top of the LED chip forming part of a LED package available from Excelitas [Aculed LED COB-Packags with an OSRAM ODB40RG chip, available from Excelitas Technologies Munich/Germany]. To attach the platelets on the LED chip, a small amount of 90% PHPS in di-n-butylether was dropped on top of the LED chip and the platelets were positioned on the PHPS-wet chip. Then the LED package was heated to 175° C. for 8 h to cure the PHPS layer. As reference materials, methyl silicone (OE-6370, DowCorning) and phenyl silicone (OE-6550 DowCorning) were used for encapsulation. The reference LEDs were prepared by spraying a mixture of silicone and YAG phosphor in a weight ratio of 1:2.5 on the LED chip and curing the coating for 4 h at 150° C. The LEDs were then operated at a current of 1.5 A at ambient conditions for 1500 h and the change in colour coordinates was measured. A generally tolerated deviation of colour coordinates after 1500 h is +/−1% which corresponds to a change in the colour coordinates of +/−0.01. The measured colour point deviation is shown in subsequent Table 4.

(207) TABLE-US-00004 TABLE 4 Deviation of colour point. Wavelength converting Δx/Δy component after 1500 h.sup.(1) Phenyl silicone (reference) +0.011/+0.033 Methyl silicone (reference) +0.005/+0.012 Example 1 ≤+/−0.001/≤+/−0.001 Example 2 ≤+/−0.006/≤+/−0.013 Example 4 ≤+/−0.001/≤+/−0.001 Example 5 ≤+/−0.001/≤+/−0.001 Example 7 ≤+/−0.001/≤+/−0.001 .sup.(1)Measurement error = +/−0.001.

(208) The wavelength converting components of Examples 1, 4, 5 and 7 were cured at temperatures of 325° C. (Examples 1, 4 and 5) or 350° C. (Example 7) and showed no detectable colour change over the complete period of 1500 h. The material of Example 2 was precured at only 150° C. and showed a colour change in between methyl and phenyl silicone. This proves the excellent colour stability of the high temperature cured wavelength converting components.

(209) To demonstrate the better barrier properties, the wavelength converting components of Example 11 were tested on LEDs operated at 350 mA in a climate chamber under 85° C. and 85% relative humidity. As reference material methyl silicone (OE-6370, DowCorning) was used for encapsulation. The reference LEDs were prepared by spraying a mixture of silicone and thiogallate phosphor in a weight ratio of 1:2.5 on the LED chip and curing the coating for 4 h at 150° C. The change in photometric intensity and colour point was measured after 500 h as shown in Table 5.

(210) TABLE-US-00005 TABLE 5 Change in photometric intensity and colour point. Wavelength converting Photometric intensity Colour change component change after 500 h.sup.(1) after 500 h Methyl silicone 52 Δx = −0.253/Δy = −0.476 (reference) Example 11 91 Δx = −0.018 /Δy = −0.029 .sup.(1)The initial intensity was normalized to 100%.

(211) The degradation of the phosphor causing the drop in photometric intensity and the change of the colour point can be observed in the emission spectra before and after the climate chamber treatment shown in FIGS. 12a and 12b.

(212) The wavelength converting component of Example 11 which was precured at 50° C. and cured at 325° C. showed a drop of intensity by 9% while the reference material methyl silicone showed a drop by 48%. This drop is caused by the degradation of the thiogallate phosphor under climate chamber conditions of 85° C. and 85% relative humidity. This result proves the improved barrier properties of the high temperature cured silazane materials. Better barrier properties allow the use of unstable phosphors, which would degrade in an inacceptable short time when used in combination with a conventional silicone encapsulant.

(213) To demonstrate the effect of the shaped platelet, the angular radiation intensity of the wavelength converting components of Example 1 (plain platelet) and Example 5 (lens-shaped platelet) attached on a LED chip was measured (see FIG. 13). The different angular intensity distribution of the plain and the lens shaped platelets demonstrates the versatility and usefulness of the production method to form wavelength converting components with specific shapes thereby controlling the angle-dependent intensity. Pouring the liquid precursor material into molds of various shapes is an easy way to produce three-dimensional wavelength converting components with variable and predictable areal light distributions.