Optoelectronic component and method for producing an optoelectronic component

Abstract

An optoelectronic component and a method for producing an optoelectronic component are disclosed. In an embodiment an optoelectronic component includes a semiconductor layer sequence having an active region configured to emit radiation at least via a main radiation exit surface during operation and a self-supporting conversion element arranged in a beam path of the semiconductor layer sequence, wherein the self-supporting conversion element includes a substrate and subsequently a first layer, wherein the first layer includes at least one conversion material embedded in a matrix material, wherein the matrix material includes at least one condensed sol-gel material, wherein the condensed sol-gel material has a proportion between 10 and 70 vol % in the first layer, and wherein the substrate is free of the sol-gel material and the conversion material and mechanically stabilizes the first layer.

Claims

1. An optoelectronic component comprising: a semiconductor layer sequence having an active region configured to emit radiation at least via a main radiation exit surface during operation; and a self-supporting conversion element arranged in a beam path of the semiconductor layer sequence, wherein the self-supporting conversion element comprises a substrate and subsequently a first layer, wherein the first layer comprises at least one conversion material embedded in a matrix material, wherein the conversion material in the matrix material has a concentration gradient, wherein the first layer comprises a surface facing away from the substrate, in which particles of the conversion material are partially not covered by the matrix material, wherein the surface is smooth, wherein the matrix material comprises at least one condensed sol-gel material selected from the group consisting of water glass, metal phosphate, monoaluminum phosphate, aluminum phosphate, modified monoaluminum phosphate, alkoxytetramethoxysilane, tetraethylorthosilicate, methyltrimethoxysilane, methyltriethoxysilane, titanium alkoxide, silica sol, metal alkoxide, metal oxane and metal alkoxane, wherein the condensed sol-gel material has a proportion between 10 and 70 vol % in the first layer, and wherein the substrate is free of the sol-gel material and the conversion material and mechanically stabilizes the first layer.

2. The optoelectronic component according to claim 1, wherein the substrate is glass, glass ceramic, sapphire, a transparent ceramic or a translucent ceramic.

3. The optoelectronic component according to claim 1, wherein the self-supporting conversion element is arranged on the main radiation exit surface by an adhesive.

4. The optoelectronic component according to claim 3, wherein the adhesive is a silicone and the self-supporting conversion element is free of silicone.

5. The optoelectronic component according to claim 3, wherein the adhesive comprises a thickness of 500 nm to 15 μm.

6. The optoelectronic component according to claim 1, wherein the first layer comprises a layer thickness between 20 μm and 70 μm for partial conversion or 30 μm to 150 μm for full conversion.

7. The optoelectronic component according to claim 1, wherein the first layer is disposed on the main radiation exit surface by an adhesive, and wherein the first layer is disposed directly on the substrate.

8. The optoelectronic component according to claim 1, wherein the optoelectronic component is configured to emit the radiation with a color temperature between 2500 K and 4500 K during the operation.

9. The optoelectronic component according to claim 1, wherein the optoelectronic component is configured to emit the radiation with a color temperature between 4500 K and 8000 K during the operation.

10. The optoelectronic component according to claim 1, wherein the condensed sol-gel material comprises a proportion between 20 and 50 vol % in the first layer.

11. The optoelectronic component according to claim 1, wherein the at least one conversion material is selected from the group consisting of (Y,Gd,Tb,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+, (Sr,Ca)AlSiN.sub.3:Eu.sup.2+, (Sr,Ba,Ca,Mg).sub.2Si.sub.5N.sub.8:Eu.sup.2+, (Ca,Sr,Ba).sub.2SiO.sub.4:Eu.sup.2+, α-SiAlON:Eu.sup.2+, β-SiAlON:Eu.sup.2+, (Sr,Ca)S:Eu.sup.2, (Sr,Ba,Ca).sub.2(Si,Al).sub.5(N,O).sub.8:Eu.sup.2+, (Ca,Sr).sub.8Mg(SiO.sub.4).sub.4Cl.sub.2:Eu.sup.2+, and (Sr,Ba)Si.sub.2N.sub.2O.sub.2:Eu.sup.2+.

12. The optoelectronic component according to claim 1, wherein at least two different conversion materials are embedded in the matrix material.

13. The optoelectronic component according to claim 1, wherein the substrate comprises a thickness of 50 μm to 200 μm.

14. The optoelectronic component according to claim 1, wherein the matrix material is the condensed sol-gel material prepared from an aluminum phosphate solution or from a monoaluminum phosphate solution or from a modified monoaluminum phosphate solution.

15. A method for producing the optoelectronic component according to claim 1, the method comprising: providing the semiconductor layer sequence comprising the active region; and applying the conversion element at least to the main radiation exit surface, wherein the conversion element is produced as follows: introducing the at least one conversion material into the matrix material to form a dispersion, wherein the matrix material comprises at least one solution of a sol-gel material selected from the group consisting of the water glass, the metal phosphate, the monoaluminum phosphate, the aluminum phosphate, the modified monoaluminum phosphate, the alkoxytetramethoxysilane, the tetraethylorthosilicate, the methyltrimethoxysilane, the methyltriethoxysilane, the titanium alkoxide, the silica sol, the metal alkoxide, the metal oxane and the metal alkoxane; applying the dispersion to the substrate to form the first layer, wherein the substrate is free of the sol-gel material and the conversion material; heating the substrate and the first layer to a maximum of 550° C.; and optionally smoothing the surface of the first layer facing away from the substrate.

16. The method according to claim 15, further comprising separating the substrate and the first layer to produce a plurality of conversion elements, wherein at least one conversion element is arranged on the main radiation exit surface.

17. The optoelectronic component according to claim 1, wherein the conversion element is free of fillers.

18. An optoelectronic component comprising: a semiconductor layer sequence having an active region configured to emit radiation at least via a main radiation exit surface during operation; and a self-supporting conversion element arranged in a beam path of the semiconductor layer sequence, wherein the self-supporting conversion element is arranged on the main radiation exit surface by an adhesive, wherein the adhesive is a silicone and the self-supporting conversion element is free of silicone, wherein the adhesive comprises a thickness of 2 μm to 7 μm, wherein the self-supporting conversion element comprises a substrate and subsequently a first layer, wherein the first layer is disposed between the main radiation exit surface and the substrate, wherein the first layer comprises a surface facing away from the substrate, in which particles of at least one conversion material are partially not covered by a matrix material, wherein the surface is smooth, wherein the at least one conversion material is embedded in the matrix material in the first layer, wherein the matrix material comprises at least one condensed sol-gel material selected from the group consisting of water glass, metal phosphate, monoaluminum phosphate, aluminum phosphate, modified monoaluminum phosphate, alkoxytetramethoxysilane, tetraethylorthosilicate, methyltrimethoxysilane, methyltriethoxysilane, titanium alkoxide, silica sol, metal alkoxide, metal oxane and metal alkoxane, wherein the condensed sol-gel material has a proportion between 10 and 70 vol % in the first layer, and wherein the substrate is free of the sol-gel material and the conversion material and mechanically stabilizes the first layer.

19. An optoelectronic component comprising: a semiconductor layer sequence having an active region configured to emit radiation at least via a main radiation exit surface during operation; and a self-supporting conversion element arranged in a beam path of the semiconductor layer sequence, wherein the self-supporting conversion element comprises a substrate and subsequently a first layer, wherein the first layer comprises at least one conversion material embedded in a matrix material, wherein the first layer comprises a surface facing away from the substrate, in which particles of the conversion material are partially not covered by the matrix material and wherein the surface is smooth, wherein the matrix material comprises at least one condensed sol-gel material selected from the group consisting of water glass, metal phosphate, monoaluminum phosphate, aluminum phosphate, modified monoaluminum phosphate, alkoxytetramethoxysilane, tetraethylorthosilicate, methyltrimethoxysilane, methyltriethoxysilane, titanium alkoxide, silica sol, metal alkoxide, metal oxane and metal alkoxane, wherein the condensed sol-gel material has a proportion between 10 and 70 vol % in the first layer, wherein the substrate is free of the sol-gel material and the conversion material and mechanically stabilizes the first layer, and wherein the substrate comprises a decoupling foil or decoupling structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described in the following in connection with the figures.

(2) Show it:

(3) FIGS. 1A to 1H show schematic side views of an optoelectronic component according to an embodiment;

(4) FIGS. 2A to 2D show optoelectronic components according to an embodiment;

(5) FIGS. 3A, 3B, 3D, 3E and 9A to 9E show the scanning of electron microscope images according to an embodiment;

(6) FIGS. 3C and 3F show surface images by means of cyber-scan profilometry according to an execution form;

(7) FIG. 4 shows the temperature as a function of the current density;

(8) FIGS. 5A to 5F show methods for producing an optoelectronic component according to an embodiment;

(9) FIG. 6 shows an optoelectronic component according to an embodiment;

(10) FIGS. 7A to 7H show data from robustness tests; and

(11) FIGS. 8A to 8D and 9F show optoelectronic components according to comparison examples or an exemplary embodiment.

(12) In the exemplary embodiments and figures, identical, similar or similarly acting elements can each be provided with the same reference numbers. The represented elements and their proportions among each other are not to be regarded as true to scale. Rather, individual elements, such as layers, components, components and areas, can be displayed in an exaggeratedly large format for better representability and/or better understanding.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(13) The FIGS. 1A to 1H each show a schematic side view of an optoelectronic component 100 according to an embodiment.

(14) The optoelectronic component 100 of FIG. 1A comprises a semiconductor layer sequence 1. The semiconductor layer sequence 1 can, for example, be made of InAlGaN. The semiconductor layer sequence comprises an active region which emits radiation at least via a main radiation exit surface 11 during operation. For example, the semiconductor layer sequence 1 emits radiation from the blue spectral range. A conversion element 2 is arranged directly on the main radiation exit surface 11. Alternatively, between conversion element 2 and semiconductor layer sequence 1, additional layers, such as an adhesive layer 3 as shown in FIGS. 1D to 1G, may be arranged.

(15) The conversion element 2 comprises a first layer 22 arranged on a substrate 21. The arrangement can be direct or indirect. Direct means here that no further layers or elements are arranged between the first layer 22 and the substrate 21 (see FIG. 1B). The first layer 22 may contain a matrix material 221, i.e., a condensed sol-gel material, for example, a water glass or metal phosphate. In the matrix material 221 can be embedded at least one conversion material 222. More than one conversion material 222 may also be embedded in the matrix material 221. Conversion material 222 can be any material configured to convert the radiation emitted by the semiconductor layer sequence 1 into radiation with a changed, usually longer, wavelength.

(16) The first layer 22 may have a structured surface 8 facing away from the substrate 21. The structuring can be carried out by polishing, grinding, etching or by coating.

(17) As shown in FIG. 1C, the conversion element 2 may have not only a first layer 22, but the first layer 22 may be formed by further sublayers 4 and 5. Conversion materials 222, 224 can be arranged in the sublayers 4, 5. The conversion materials 222, 224 can be the same or different. The conversion materials 222, 224 are each embedded in a matrix material 221, 223. The matrix material 221, 223 can be, for example, water glass or metal phosphate. The matrix material 221, 223 of the sublayer 4 and the sublayer 5 may be identical or different. The sublayers 4, 5 can be arranged on the substrate 21. The substrate 21 can be glass, glass ceramic, sapphire or transmissive ceramic.

(18) FIG. 1D shows that an adhesive layer 3 is arranged between the semiconductor layer sequence 1 and the conversion element 2.

(19) As shown in FIG. 1E, the substrate 21 may be located between the main radiation exit surface 11 (not shown here) and the first layer 22. The substrate 21 can therefore be directly downstream of the adhesive layer 3 or the main radiation exit surface 11.

(20) Alternatively, as shown in FIG. 1F, the first layer 22 may be located between the main radiation exit surface 11 (not shown here) and the substrate 21. The first layer 22 can therefore be placed directly after the adhesive layer 3 or the main radiation exit surface 11.

(21) FIG. 1G shows the arrangement of the optoelectronic component 100 in a housing 7. The housing can have a recess in which the optoelectronic component 100 is arranged. The recess can be filled with a potting 6, for example, silicone or another inorganic potting material.

(22) FIG. 1H shows the arrangement of the optoelectronic component 100 in a housing 7. The housing can have a recess in which the optoelectronic component 100 is arranged. The recess can be filled with a potting 6, for example, silicone or another inorganic potting material. Contrary to the embodiment of FIG. 1G, here the potting 6 is only filled up to the upper edge of the conversion element. The potting 6 may contain silicone filled with TiO.sub.2 particles, for example.

(23) FIGS. 2A and 2B each show scanning electron microscope images of a conversion element 2 according to an embodiment.

(24) FIG. 2A shows a glass substrate 21 on which a first layer of 22 is arranged. The first layer shows roughening on its surface 8, which faces away from the substrate 21. In comparison, as shown in FIG. 2B, this surface 8 is smoothed. Smoothing can be done by polishing or grinding, for example. Very thin first layers 22 can be produced, for example, with a layer thickness of <50 μm.

(25) An optoelectronic component 100 can thus be made available which, like a silicone matrix, comprises all the color coordinates and a high color rendering index. In comparison to a silicone matrix, however, the component 100 can be operated at high operating currents, current densities and temperatures. As shown in FIGS. 2C and D, the optoelectronic component 100 can also be arranged in matrix form. The lateral expansion of the conversion element can be 1 mm×1 mm or approximately 1.3 mm×1.5 mm.

(26) The FIGS. 3A to 3F show the comparison of conversion elements that are polished (FIGS. 3D to 3F) or unpolished (FIGS. 3A to 3C).

(27) FIG. 3A shows a scanning electron microscope (SEM) image in which the matrix material 221 is aluminum phosphate, wherein the first layer 22 comprises no polished surface. FIG. 3B shows the corresponding cross-section after gluing onto a semiconductor layer sequence 1 and FIG. 3C shows the corresponding cyber-scan profilometry.

(28) In comparison, FIG. 3D shows a polished surface of the first layer 22 where the matrix material 221 is aluminum phosphate, FIG. 3E shows a cross-section of a polished first layer after gluing to a semiconductor layer sequence 1 and FIG. 3F shows a cyber scan profilometry.

(29) It can be seen that by using a polished surface, the particles of the conversion material are ground down and thus the thickness of the adhesive layer 3 can also be reduced. For example, polishing can reduce the layer thickness of the adhesive layer 3 from the original 15 μm, so unpolished, to 5 μm and thus increase heat dissipation, thus enabling a higher operating current density.

(30) FIG. 4 shows the converter temperature T in ° C. measured from the side of the conversion element facing away from the semiconductor layer sequence as a function of the operating current density I in A/mm.sup.2 of a semiconductor layer sequence 4-1 which emits only blue light, a conversion element 4-2 which comprises a polished surface 8, a conversion element 4-3 which comprises an unpolished surface 8, and as reference R a conversion element with a conversion material 222 in the matrix material silicone.

(31) It can be seen from the figure that a significant reduction in the converter temperature of a polished conversion material, in which, for example, aluminum phosphate is used as matrix material, can be produced at high operating currents of 3 A/mm.sup.2. The application of a conversion material to a substrate, particularly glass, allows the use of higher operating currents and densities and a higher luminous flux per chip area for warm white applications.

(32) FIGS. 5A to 5F show a method for producing an optoelectronic component according to an embodiment. In particular, a conversion element 2 is produced here. A conversion material 222 is provided and introduced into a liquid sol-gel material 221. A dispersion is generated (see FIG. 5B). This dispersion can be applied to a cleaned substrate 21. The cleaning can be done, for example, with a solvent or with ultrasound or by plasma treatment. The volume proportion of the matrix material 221 in the first layer 22 is between 10 and 70 vol %. The mixing to produce the dispersion can be carried out by homogenization. As shown in FIG. 5C, the dispersion can then be applied to a substrate, such as glass, by doctor-blading. Then it can be heated to 350° C., for example. The heating can take place in an oven, for example. If necessary, the surfaces of the conversion material can then be smoothed as shown in FIG. 2E. Subsequently, a separation can optionally be carried out so that several conversion elements can be generated cost-effectively, as shown in FIG. 5F. The separation can, for example, be carried out using a saw.

(33) FIG. 6 shows an area 6-1 of the surface of conversion element 2 treated with sandblasting. This reduces the yellowish color impression perceived by the external observer. In addition, the light extraction can be improved and the efficiency increased and/or color location homogeneity over angle can be improved.

(34) FIGS. 7A to 7H each show different robustness tests of the optoelectronic components described here. FIGS. 7A, 7C, 7E and 7G show the dependence on Iv in % and time t in h. Here Iv denotes the luminous intensity measured perpendicular to the main radiating surface relative to the value at 0 h. The FIGS. 7B, 7D, 7F and 7H show the dependency of Δx in units of 0.001 and the time t in h. Δx denotes the absolute change of the x-component of the color location (in the CIE standard color chart) of the total radiation of the component compared to the x-component at 0 h.

(35) As matrix material 221 aluminum phosphate is used, as green conversion material 222 LuAG:Ce and as red conversion material 224 CaAlSiN:Eu. The substrate 21 is a glass substrate with a thickness of 170 μm. The glass is from the company Schott and has the trade name D263. The tests were carried out at different temperatures and operating currents or at a defined temperature and humidity with an area of the semiconductor layer sequence of approx. 1 mm×1 mm. All illustrations show that the optoelectronic components 100 described here have a high stability at high temperatures and operating currents or temperature and humidity.

(36) The FIGS. 8A to 8D each show conversion elements as comparison examples (FIGS. 8A to 8C) and an exemplary embodiment (FIG. 8D). The conversion element of FIG. 8A uses silicone as matrix material, the conversion element of FIG. 8B has a ceramic converter, the conversion element of FIG. 8C uses conventional glass as matrix material and the conversion element of FIG. 8D is the conversion element for the component described here with the condensed sol-gel materials described here as matrix material 221 (g—green, y—yellow, r—red, w—warm white).

(37) The component of FIG. 8A cannot be used at high temperatures due to the silicone, as silicone degrades. The component of FIG. 8B can be used for high power optoelectronic components, but no mixture of conversion materials can be used and no warm white components can be provided. This limits the color rendering index of these conversion materials. Although warm white optoelectronic components can be produced for the component of FIG. 8C, these are usually also limited in terms of the color rendering index. The optoelectronic component invented here can overcome all these disadvantages and shows the advantage that by using the inorganic condensed sol-gel material, such as aluminum phosphate, monoaluminum phosphate or modified monoaluminum phosphate, all conventional conversion materials can be mixed in and thus a component with a high luminance and stability can be provided.

(38) In the following, optoelectronic components are each described according to an embodiment.

EXAMPLE 1

Aluminum Phosphate.SUP.6 .Warm White Converter With High CRI and R9

(39) A suspension of aluminum phosphate with a warm white phosphor mixture.sup.1 is produced. Optionally, the suspension can be diluted with distilled water to adjust viscosity. The solid to liquid mass ratio should be between 1:2 and 1:0.3, in particular between 1:1.5 and 1:0.4, ideally 1:0.5. For example, the suspension is applied to a substrate.sup.2 using doctor blading. The doctor blade gap can be between 10-200 μm, in particular between 30-100 μm and ideally between 40-80 μm. The application speed is typically varied between 1-99 mm/sec. After the coating process, the freshly coated substrate is pre-dried under normal air, a clean room or a drying cabinet. The room temperature and humidity can be kept constant between 18-50° C. and 0-80 g/m.sup.3, in particular between 18-30° C. and 0-50 g/m.sup.3 and ideally between 19-23° C. and 0-30 g/m.sup.3. After pre-drying, the substrate is typically cut into equal parts with a diamond cutter and baked at temperatures between 150° C.-450° C. for 10 to 120 minutes.

(40) FIGS. 9A and 9B show two exemplary SEM images (top view) of a sample with aluminum phosphate and warm white phosphor mixture.

(41) FIG. 9c shows an exemplary side view of a sample with aluminum phosphate and warm white phosphor mixture. H means high voltage, A means working distance and V means magnification.

(42) After baking, the substrates are further refined by polishing, lapping, grinding or a combination of the various methods.

(43) FIG. 9D shows an exemplary SEM image of a polished aluminum phosphate warm white coating.

(44) FIG. 9E shows an exemplary SEM image of a polished aluminum phosphate warm white coating. After the final surface treatment, the substrate is typically cut using a wafer or laser saw into converters measuring 1 mm×1 mm, for example.

(45) FIG. 9F shows an image of a sawn aluminum phosphate warm white converter.

EXAMPLE 2

Aluminum Phosphate.SUP.6 .Cold White Converter

(46) A suspension of aluminum phosphate with a garnet phosphor.sup.3 is produced. Optionally, the suspension can be supplemented with at least one additional phosphor, for example, to vary the CRI, R9, the emission color or color temperature. In addition, the viscosity can be adjusted by adding distilled water. The solid to liquid mass ratio can be between 1:2 and 1:0.3, in particular between 1:1.5 and 1:0.4, ideally 1:0.5. For example, the suspension is applied to a substrate.sup.2 using doctor blading. The doctor blade gap can be between 10-200 μm, in particular between 30-100 μm and ideally between 40-80 μm. The application speed can be varied between 1-99 mm/sec. After the coating process, the freshly coated substrate is pre-dried under normal air, in a clean room or a drying cabinet. The room temperature and humidity can be kept constant between 18-50° C. and 0-80 g/m.sup.3, in particular between 18-30° C. and 0-50 g/m.sup.3 and ideally between 19-23° C. and 0-30 g/m.sup.3. After pre-drying, the substrate can typically be cut into equal parts with a diamond cutter and baked at temperatures between 150° C.-450° C. for 10 to 120 minutes.

(47) After baking, the substrates can be further refined by polishing, lapping, grinding or a combination of the various methods. After the final surface treatment, the substrate can typically be cut using a wafer or laser saw into converters measuring 1 mm×1 mm, for example.

EXAMPLE 3

Aluminum Phosphate.SUP.6 .Red Converter

(48) A suspension of aluminum phosphate with a nitridic phosphor.sup.4 is prepared. Optionally, the suspension can be supplemented with at least one additional phosphor, for example, to vary the CRI, R9, emission color or color temperature. In addition, the viscosity can be adjusted by adding distilled water. The solid to liquid mass ratio can be between 1:2 and 1:0.3, in particular between 1:1.5 and 1:0.4, ideally 1:0.5. For example, the suspension is applied to a substrate.sup.2 using doctor blading. The doctor blade gap can be between 10-200 μm, in particular between 30-100 μm and ideally between 30-70 μm. The application speed can typically be varied between 1-99 mm/sec. After the coating process, the freshly coated substrate is pre-dried under normal air, in a clean room or a drying cabinet. The room temperature and humidity can be kept constant between 18-50° C. and 0-80 g/m.sup.3, in particular between 18-30° C. and 0-50 g/m.sup.3 and ideally between 19-23° C. and 0-30 g/m.sup.3. After pre-drying, the substrate can typically be cut into equal parts with a diamond cutter and baked at temperatures between 150° C.-450° C. for 10 to 120 minutes.

(49) After baking, the substrates can be further refined by polishing, lapping, grinding or a combination of the various methods. After the final surface treatment, the substrate can typically be cut using a wafer or laser saw into converters measuring 1 mm×1 mm, for example.

EXAMPLE 4

Aluminum Phosphate.SUP.6 .Phosphors Converter

(50) A suspension of aluminum phosphate with a phosphors or conversion material is produced. Optionally, the suspension can be supplemented with at least one additional phosphor or conversion material, for example, to vary the CRI, the emission color or the color temperature. In addition, the viscosity can be adjusted by adding distilled water. The solid to liquid mass ratio can be between 1:2 and 1:0.3, in particular between 1:1.5 and 1:0.4, ideally 1:0.5. For example, the suspension is applied to a substrate.sup.2 using doctor blading. The doctor blade gap can be between 10-200 μm, in particular between 30-100 μm and ideally between 40-80 μm. The application speed can typically be varied between 1-99 mm/sec. After the coating process, the freshly coated substrate is pre-dried under normal air, in a clean room or a drying cabinet. The room temperature and humidity can be kept constant between 18-50° C. and 0-80 g/m.sup.3, in particular between 18-30° C. and 0-50 g/m.sup.3 and ideally between 19-23° C. and 0-30 g/m.sup.3. After pre-drying, the substrate can typically be cut into equal parts with a diamond cutter and baked at temperatures between 150° C.-450° C. for 10 to 120 minutes.

(51) After baking, the substrates can be further refined by polishing, lapping, grinding or a combination of the various methods. After the final surface treatment, the substrate can typically be cut using a wafer or laser saw into converters measuring 1 mm×1 mm, for example.

(52) .sup.1Warm white phosphor mixture for high CRI and R9 applications: Garnet phosphor (e.g., (Lu,Y,Gd,Tb,Ce).sub.3(Al,Ga).sub.5O.sub.12, especially (Y,Lu,Ce).sub.3(Al,Ga).sub.5O.sub.12, especially (Lu,Ce).sub.3(Al.sub.1-xGax).sub.5O.sub.12 with a Ga content of 0%<=x<=60%) with at least one ⋅“258”: M.sub.2(Al,Si).sub.5(N,O)8-like phosphor doped with Eu (M=Ca, Sr, Ba, Mg) or a phosphor derived therefrom and/or “(S)CASN”: phosphor as in EP 1696016 A1 or

(53) WO 2005052087 A1, the disclosure content of which is hereby taken up by withdrawal, for example (Sr,Ca)AlSi(N,O).sub.3:Eu and/or A “226” phosphor with an activator content of >=0.5%, especially >=2%, especially >=3% with divalent metals such as Sr and/or Ca, for example Sr(Sr,Ca)Si.sub.2Al.sub.2N.sub.6:Eu The suspension is typically produced in a speed mixer or ball mill.

(54) .sup.2Alternative Substrate Materials sapphire (reflective) metal substrate Polymer film or substrate ceramic substrate Pre-coated substrates, e.g., glass substrate with Al.sub.2O.sub.3 coating Before coating, for example, a plasma process can be carried out to clean or activate the surface.

(55) .sup.3Chemical Composition of a Garnet Phosphor Garnet phosphor (e.g., (Lu,Y,Gd,Tb,Ce).sub.3(Al,Ga).sub.5O.sub.12, especially (Y,Lu,Ce).sub.3(Al,Ga).sub.5O.sub.11, especially (Lu,Ce).sub.3(Al.sub.1-xGax).sub.5O.sub.12 with a Ga content of 0%<=x<=60%)

(56) .sup.4 Chemical Compositions of a Nitride Phosphor ⋅“258”: M.sub.2(Al,SO.sub.5(N,O)8-like phosphor doped with Eu (M=Ca, Sr, Ba) or phosphor derived therefrom, for example (Sr,Ba,Ca,Mg).sub.2Si.sub.5N8:Eu (S)CASN”: phosphor as described in EP1696016 A1/WO 2005052087 A1, for example (Sr,Ca)AlSi(N,O).sub.3:Eu and/or A “226” phosphor with an activator content of >=0.5%, especially >=2%, especially >=3% with divalent metals such as Sr and/or Ca, for example Sr(Sr,Ca)Si.sub.2Al.sub.2N.sub.6:Eu

(57) .sup.5Phosphor

(58) (Y,Gd,Tb,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+

(59) (Sr,Ca)AlSiN.sub.3:Eu.sup.2+

(60) (Sr,Ba,Ca,Mg).sub.2Si.sub.5N.sub.8:Eu.sup.2+

(61) (Ca,Sr,Ba).sub.2SiO.sub.4:Eu.sup.2+

(62) α-SiAlON:Eu.sup.2+

(63) β-SiAlON:Eu.sup.2+

(64) (Sr,Ca)S:Eu.sup.2

(65) (Sr,Ba,Ca).sub.2(Si,Al).sub.5(N,O).sub.8:Eu.sup.2+

(66) (Ca,Sr).sub.8Mg(SiO.sub.4).sub.4Cl.sub.2:Eu.sup.2+

(67) (Sr,Ba)Si.sub.2N.sub.2O.sub.2:Eu.sup.2+

(68) .sup.6Alternative Matrix Materials Potassium water glass with aluminum phosphate hardener lithium water glass mixed water glass, for example, lithium water glass:potassium water glass with a mass fraction of 1 to 1

(69) The exemplary embodiments described in connection with the figures and their features can also be combined with each other according to further exemplary embodiments, even if such combinations are not explicitly shown in the figures. Furthermore, the exemplary embodiments described in connection with the figures may have additional or alternative features as described in the general part.

(70) The invention is not limited by the description based on the exemplary embodiments of these. Rather, the invention includes any new feature as well as any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or combination itself is not explicitly mentioned in the patent claims or exemplary embodiments.