Luminophore mixtures for use in dynamic lighting systems
10907095 ยท 2021-02-02
Assignee
Inventors
- Andreas Benker (Lautertal, DE)
- Ralf Petry (Griesheim, DE)
- Ingo Koehler (Darmstadt, DE)
- Irene (Yu Huan) Liu (Taipei, TW)
- Christof HAMPEL (Frankfurt Am Main, DE)
- Aleksander Zych (Darmstadt, DE)
Cpc classification
H01S5/0609
ELECTRICITY
C09K11/77348
CHEMISTRY; METALLURGY
International classification
H01L27/15
ELECTRICITY
H01S5/06
ELECTRICITY
Abstract
The present invention relates to novel phosphor mixtures and to a light-emitting device which comprises at least one of the novel phosphor mixtures. The phosphor mixtures can be used in phosphor-converted LEDs with a semiconductor that emits in the violet spectral region. The present invention furthermore relates to a lighting system which may comprise the light-emitting devices according to the invention, and to a dynamic lighting system. The present invention furthermore relates to a process for the preparation of the phosphor mixtures according to the invention and to the use thereof in light-emitting devices for use in general lighting and/or in specialty lighting.
Claims
1. Phosphor mixture comprising: i.) one or more compounds (i) of the formula (1) or formula (2)
(Ba,Sr,Ca).sub.2cM.sup.1.sub.cMg.sub.1dM.sup.2.sub.dSi.sub.2O.sub.7ef+dF.sub.eCl.sub.f:Eu,Mn(formula (1)) where: M.sup.1=one or more alkali-metal elements; M.sup.2=Zr and/or Hf; 0c0.3; 0d0.3; 0e0.3; and 0f0.3;
(Ba,Sr,Ga).sub.avyA.sub.yM.sup.1.sub.beM.sup.2.sub.eM.sup.3.sub.vO.sub.ceyN.sub.e+vX.sub.x+y;Eu(formula (2)) where: A=Na and/or K; M.sup.1=B, Al, Ga, In, Tl and/or Sc; M.sup.2=Si and/or Ge; M.sup.3=Y, Lu and/or La; X=F and/or Cl; 0.65a1.0; 0y0.1.Math.a; 10.667b11.133; 0e5.0; 0v0.1.Math.a; 17.00c17.35; 0x5.0; 0.0584a/b0.0938; 0.0375a/c0.0588; and 2.Math.a+3.Math.b=2.Math.c+x if v=0; ii.) one or more compounds (ii), selected from the group of blue- or cyan-emitting phosphors consisting of (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+; (Sr,Ba).sub.10(PO.sub.4).sub.6Cl.sub.2:Eu; BaMgAl.sub.10O.sub.17:Eu.sup.2+; Sr.sub.4Al.sub.14O.sub.25:Eu.sup.2+; BaSi.sub.2O.sub.2N.sub.2:Eu.sup.2+; Lu.sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+; LiCaPO.sub.4:Eu.sup.2+ and mixtures thereof; and/or iii.) one or more compounds (iii), selected from the group of orange- or red-emitting phosphors consisting of (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+; (1x)(Sr,Ca)AlSiN.sub.3.x(Si.sub.2N.sub.2O):Eu.sup.2+ (where 0<x<1); (Sr,Ca)AlSiN.sub.3:Eu.sup.2+; (Ca.sub.1xSr.sub.x)S:Eu.sup.2+ (where 0x1); SrLiAl.sub.3N.sub.4:Eu.sup.2+; 3.5 MgO.0.5 MgF.sub.2.GeO.sub.2:Mn.sup.4+; K.sub.2(Si,Ti)F.sub.6:Mn.sup.4+; (Ba,Sr,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+,Mn.sup.2+; Ba.sub.2(Lu,Y,Gd).sub.1xTb.sub.x(BO.sub.3).sub.2Cl:Eu.sup.2+/3+ (where 0x1); Ba.sub.2Mg(BO.sub.3).sub.2:Eu.sup.2+; La.sub.2O.sub.2S:Eu.sup.3+; (Sr,Ca,Ba).sub.2Si.sub.5N.sub.8:Eu.sup.2+; (Sr,Ca,Ba).sub.2Si.sub.5xAl.sub.xN.sub.8xO.sub.x:Eu.sup.2+ (where 0x3.0); EA.sub.dEu.sub.cE.sub.eN.sub.fO.sub.x (where EA=Ca, Sr and/or Ba; E=Si and/or Ge; 0.80d1.995; 0.005c0.2; 4.0e6.0; 5.0f8.7; 0x3.0; and 2.Math.d+2.Math.c+4.Math.e=3.Math.f+2.Math.x); A.sub.20.5yxEu.sub.xSi.sub.5N.sub.8yO.sub.y (where A=Ca, Sr and/or Ba; 0.005x1.0; and 0.1y3.0); Ma.sub.2y(Ca,Sr,Ba).sub.1xySi.sub.5zMe.sub.zN.sub.8:Eu.sub.xCe.sub.y (where Ma=Li, Na and/or K; Me=Hf.sup.4+ and/or Zr.sup.4+; 0.0015x0.20; 0y0.15; and z<4.0) and mixtures thereof; characterised in that condition (A) or (B) is satisfied:
w(i)=35 to 95% by weight,
w(ii)=0 to 5.0% by weight and
w(iii)=>5.0 to 50% by weight;(A)
w(i)=35 to 85% by weight,
w(ii)=5.0 to 65% by weight and
w(iii)=0 to 45% by weight;(B) where w(i) denotes the proportion by weight (% by weight) of compound (i), w(ii) denotes the proportion by weight (% by weight) of compound (ii) and w(iii) denotes the proportion by weight (% by weight) of compound (iii), in each case based on the total weight of the phosphor mixture; with the proviso that phosphor mixtures comprising 31.7% by weight of Sr.sub.2.5Eu.sub.0.12Ca.sub.0.38MgSi.sub.2O.sub.8; 63.5% by weight of Ba.sub.1.9Eu.sub.0.1Mg.sub.0.95Zr.sub.0.05Si.sub.2O.sub.7.05; and 4.8% by weight of CaAlSiN.sub.3:Eu are excluded.
2. Phosphor mixture according to claim 1, characterised in that the compounds (i) of the formula (1) are represented by the formula (3):
Ba.sub.2abcxSr.sub.aCa.sub.bM.sup.1.sub.cMg.sub.1dyM.sup.2.sub.dSi.sub.2O.sub.7ef+dF.sub.eCl.sub.f:Eu.sub.x,Mn.sub.y(formula (3)) where: M.sup.1=Li, Na, K and/or Rb; M.sup.2=Zr and/or Hf; 0a1.999; 0b1.999; 0c0.3; 0d0.3; 0e0.3; 0f0.3; 0.001x0.3; and 0y0.3.
3. Phosphor mixture according to claim 2, characterised in that, in formula (3), c=0, e=0 and f=0.
4. Phosphor mixture according to claim 2, characterised in that, in formula (3), d is =0.
5. Phosphor mixture according to claim 2, characterised in that, in formula (3), y is =0.
6. Phosphor mixture according to claim 2, characterised in that, in formula (3), b is =0.
7. Phosphor mixture according to claim 1, characterised in that the compounds (i) of the formula (2) are represented by the formula (4):
(Ba,Sr,Ca).sub.advyEu.sub.dA.sub.yM.sup.1.sub.beM.sup.2.sub.eM.sup.3.sub.vO.sub.ceyN.sub.e+vX.sub.x+y(formula (4)) where: A=Na and/or K; M.sup.1=B, Al, Ga, In, Tl and/or Sc; M.sup.2=Si and/or Ge; M.sup.3=Y, Lu and/or La; X=F and/or Cl; 0.65a1.0; 0d1.0; 0y0.1.Math.a; 10.667b11.133; 0e5.0; 0v0.1.Math.a; 17.00c17.35; 0x5.0; 0.0584a/b0.0938; 0.0375a/c0.0588; and 2.Math.a+3.Math.b=2.Math.c+x if v=0.
8. Phosphor mixture according to claim 7, characterised in that the following applies in formula (4): 0.0005x+y1.0, preferably 0.001x+y0.1, more preferably 0.001x+y0.05; 0.70a0.80; 0e0.5; 0.03d0.25; 10.93b11.067; and 17.20c17.30.
9. Phosphor mixture according to claim 1, characterised in that it comprises one or more compounds (ii) and one or more compounds (iii).
10. Phosphor mixture according to claim 1, characterised in that conditions (A) and (B) are defined as follows:
w(i)=40 to 95% by weight,
w(ii)=0 to 5.0% by weight and
w(iii)=>5.0 to 50% by weight;(A)
w(i)=35 to 85% by weight,
w(ii)=5.0 to 65% by weight and
w(iii)=3.5 to 45% by weight.(B)
11. Process for the preparation of a phosphor mixture according to claim 1, comprising the steps: a) weighing-out of a weight m(i) of phosphor (i), a weight m(ii) of phosphor (ii) and/or a weight m(iii) of phosphor (iii); and b) mixing of the weights of phosphors (i), (ii) and/or (iii) weighed out in step a).
12. Light-emitting device which comprises at least one primary light source and at least one phosphor mixture according to claim 1.
13. Light-emitting device according to claim 12, characterised in that the primary source is a light-emitting semiconductor diode (SLED), a semiconductor laser diode (LD), an organic light-emitting diode (OLED) or a plasma or discharge source.
14. Lighting system comprising at least two light-emitting devices, where the at least two light-emitting devices emit light having an identical colour location and/or an identical colour rendering index and/or an identical correlated colour temperature and where the light from the at least two light-emitting devices differs from one another with respect to the spectral composition, characterised in that each of the at least two light-emitting devices comprises at least two different phosphors, where at least one of the phosphors can be excited by violet light and optionally by ultraviolet light and has a relative excitability at 450 nm of 65% and where the maximum excitability in the excitation spectrum corresponds to 100%.
15. Lighting system comprising at least two light-emitting devices, where the at least two light-emitting devices emit light having an identical colour location and/or an identical colour rendering index and/or an identical correlated colour temperature and where the light from the at least two light-emitting devices differs from one another with respect to the spectral composition, characterised in that each of the at least two light-emitting devices comprises at least two different phosphors, where at least one of the phosphors can be excited by violet light and optionally by ultraviolet light and has a relative excitability at 450 nm of 65% and where the maximum excitability in the excitation spectrum corresponds to 100%, where the at least two light-emitting devices are light-emitting devices according to claim 12.
16. Lighting system according to claim 14, characterised in that it is a dynamic lighting system.
17. Dynamic lighting system which comprises at least two light emitting devices according to claim 12, where the at least two light-emitting devices emit light having an identical colour location and/or an identical colour rendering index and/or an identical correlated colour temperature, characterised in that the light from the at least two light-emitting devices differs from one another with respect to the spectral composition.
18. A process for the conversion of blue, violet and/or ultraviolet radiation into light having a longer wavelength, comprising subjecting said radiation to a light-emitting device comprising a phosphor mixture according to claim 1.
19. The process according to claim 18, where the light-emitting device is a light-emitting diode (LED) for use in general lighting and/or in specialty lighting.
20. Lighting system comprising at least two light-emitting devices, where the at least two light-emitting devices emit light having an identical colour location and/or identical colour rendering index and/or an identical correlated colour temperature and where the light from the at least two light-emitting devices differs from one another with respect to the spectral composition, characterised in that each of the at least two light-emitting devices comprises at least two different phosphors, where at least one of the phosphors can be excited by violet light and optionally by ultraviolet light and has a relative excitability at 450 nm of 65% and where the maximum excitability in the excitation spectrum corresponds to 100%, where the at least two light-emitting devices are light-emitting devices according to claim 13.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
DEFINITIONS
(7) As used in the present application, the terms phosphor or conversion phosphor, which are used as synonyms here, denote a fluorescent inorganic material in particle form having one or more emitting centres. The emitting centres are formed by activators, usually atoms or ions of a rare-earth metal element, such as, for example, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and/or atoms or ions of a transition-metal element, such as, for example, Cr, Mn, Fe, Co, Ni, Cu, Ag, Au and Zn, and/or atoms or ions of a main-group metal element, such as, for example, Na, Tl, Sn, Pb, Sb and Bi. Examples of phosphors or conversion phosphors include garnet-based phosphors, silicate-based, orthosilicate-based, thiogallate-based, sulfide-based and nitride-based phosphors. Phosphor materials in the sense of the present invention have no quantum confining effects. Non-quantum-confined phosphor materials of this type can be phosphor particles with or without silicon dioxide coating. A phosphor or conversion phosphor in the sense of the present application is taken to mean a material which absorbs radiation in a certain wavelength region of the electromagnetic spectrum, preferably in the blue, violet or ultraviolet spectral region, and emits visible light in another wavelength region of the electromagnetic spectrum, preferably in the red, orange, yellow, green, cyan or blue spectral region. The term radiation-induced emission efficiency should also be understood in this connection, i.e. the conversion phosphor absorbs radiation in a certain wavelength region and emits radiation in another wavelength region with a certain efficiency. The term shift in the emission wavelength is taken to mean that a conversion phosphor emits light at a different wavelength, i.e. shifted towards a shorter or longer wavelength, compared with another or similar conversion phosphor.
(8) The phosphor mixture according to the invention can be in the form of a loose material, powder material, thick or thin layer material or self-supporting material in the form of a film. It may furthermore be embedded in an encapsulation material. The individual phosphors in the phosphor mixture may include supplementary materials, such as, for example, one or more coating materials.
(9) The term encapsulation material relates to a light-transmitting matrix material which encapsulates the phosphor mixtures according to the invention. The light-transmitting matrix material can be a silicone, a polymer (which is formed from a liquid or semi-solid precursor material, such as a monomer), an epoxide, a glass or a hybrid of a silicone and epoxide. Specific, but non-limiting examples of polymers include fluorinated polymers, polyacrylamide polymers, polyacrylic acid polymers, polyacrylonitrile polymers, polyaniline polymers, polybenzophenone polymers, poly(methyl methacrylate) polymers, silicone polymers, aluminium polymers, polybispheno polymers, polybutadiene polymers, polydimethylsiloxane polymers, polyethylene polymers, polyisobutylene polymers, polypropylene polymers, polystyrene polymers, polyvinyl polymers, polyvinylbutyral polymers or perfluorocyclobutyl polymers. Silicones may include gels, such as, for example, Dow Corning OE-6450, elastomers, such as, for example, Dow Corning OE-6520, Dow Corning OE-6550, Dow Corning OE-6630, and resins, such as, for example, Dow Corning OE-6635, Dow Corning OE-6665, Nusil LS-6143 and other products from Nusil, Momentive RTV615, Momentive RTV656 and many other products from other manufacturers. Furthermore, the encapsulation material can be a (poly)silazane, such as, for example, a modified organic polysilazane (MOPS) or a perhydropolysilazane (PHPS). The content of the phosphor mixture, based on the encapsulation material, is preferably in the range from 3 to 80% by weight.
(10) The term coating material denotes a material which forms a coating on the surface of a phosphor particle. The term coating is used here to describe one or more layers of a material which is provided on another material and partly or completely covers the outer surface or the solvent-accessible surface of the other material. The material of the coating (coating material) may penetrate at least partially into the inner structure of the phosphor which has been coated, so long as the coating as barrier still provides adequate protection against external physical influences or the passage of possibly harmful substances, such as, for example, oxygen, moisture and/or free radicals. This increases the stability of the phosphor, which leads to improved durability and service life. In addition, the coating material in some embodiments provides the phosphor with additional functionality, such as, for example, reduced sensitivity to heat, reduced light refraction or improved adhesion of the phosphor material in polymers or encapsulation materials. Furthermore, unevenness on the surface of the particles of the phosphor can be smoothed by the application of one or more coating materials. Such surface smoothing enables good processability of the phosphor and reduces undesired optical scattering effects of the emitted light at the surface of the material, which results in increased efficiency.
(11) Suitable materials for the coating are, in particular, metal oxides and nitrides, in particular alkaline-earth metal oxides, such as Al.sub.2O.sub.3, and alkaline-earth metal nitrides, such as AlN, as well as SiO.sub.2. The coating can be carried out here, for example, by fluidised-bed methods or wet-chemical methods. Suitable coating methods are known, for example, from JP 04-304290, WO 91/10715, WO 99/27033, US 2007/0298250, WO 2009/065480 and WO 2010/075908. The aim of the coating may be on the one hand higher stability of the phosphors, for example to air or moisture. However, the aim may also be improved coupling-in and out of light through a suitable choice of the surface of the coating and of the refractive indices of the coating material.
PREFERRED EMBODIMENTS OF THE INVENTION
(12) Phosphor Mixture
(13) The present invention relates to a phosphor mixture comprising one or more compounds (i) of the formula (1) or formula (2), one or more compounds (ii), selected from the group of blue- and cyan-emitting phosphors, and/or one or more compounds (iii), selected from the group of orange- or red-emitting phosphors, as defined in claim 1. The phosphor mixture according to the invention thus comprises one or more compounds (i) and at least one or more further compounds selected from compounds (ii) and (iii). Possible phosphor mixtures are thus phosphor mixtures which comprise one or more compounds (i) and one or more compounds (ii); phosphor mixtures which comprise one or more compounds (i) and one or more compounds (iii); and phosphor mixtures which comprise one or more compounds (i) and one or more compounds (ii) and one or more compounds (iii).
(14) The compounds of the formula (1) are pyrosilicate phosphors, which are known from WO 2016/173692 A1. The compounds of the formula (2) are alkaline-earth metal aluminate phosphors, which are known from WO 2016/150547 A1. The disclosure content of WO 2016/173692 A1 and the disclosure content of WO 2016/150547 A1 are hereby incorporated into the present patent application by way of reference.
(15) It goes without saying that the compounds (i) of the formula (1) or formula (2), and the corresponding preferred embodiments, are charge-neutral, i.e. the positive charges of the cationic elements of the lattice and the negative charges of the anionic elements of the lattice cancel each other out.
(16) In a preferred embodiment, the compound (i) of the formula (1) in the phosphor mixture according to the invention is represented by the formula (3):
Ba.sub.2abcxSr.sub.aCa.sub.bM.sup.1.sub.cMg.sub.1dyM.sup.2.sub.dSi.sub.2O.sub.7ef+dF.sub.eCl.sub.f:Eu.sub.x,Mn.sub.y(formula (3)) where: M.sup.1=Li, Na, K and/or Rb; M.sup.2=Zr and/or Hf; 0a1.999, more preferably 0a1.0, most preferably 0a0.4; 0b1.999, more preferably 0b1.0, most preferably 0b0.4; 0c0.3, more preferably 0c0.2; 0d0.3, more preferably 0d0.2; 0e0.3, more preferably 0e0.2; 0f0.3, more preferably 0f0.2; 0.001x0.3, more preferably 0.005x0.2; and 0y0.3.
(17) For compounds of the formula (3) where c0, which contain M.sup.1, the following preferably applies to the index c: 0.001c0.3, more preferably 0.01c0.2.
(18) For compounds of the formula (3) where d0, which contain M.sup.2, the following preferably applies to the index d: 0.001d0.2, more preferably 0.01d0.1.
(19) If the compound (i) of the formula (1) or (3) contains more than one of the elements Ba, Sr and Ca, the ratio of Ba, Sr and Ca can be adjusted freely within the pre-specified empirical formula. The compound (i) of the formula (1) or (3) preferably contains not more than one of the elements Ba, Sr and Ca, preferably Ba or Sr.
(20) If the compound (i) of the formula (1) contains more than one of the elements M.sup.1, the ratio of the alkali-metal elements can be adjusted freely within the pre-specified empirical formula. If the compound (i) of the formula (3) contains more than one of the elements M.sup.1, the ratio of Li, Na, K and Rb can be adjusted freely within the pre-specified parameters. M.sup.1 in formulae (1) and (3) is preferably Na and/or K.
(21) If the compound (i) of the formula (1) or (3) contains more than one of the elements M.sup.2, the ratio of Zr and Hf can be adjusted freely within the pre-specified empirical formula. M.sup.2 in formulae (1) and (3) is preferably Zr.
(22) If the compound (i) of the formula (1) or (3) contains more than one of the elements F and Cl, the ratio of F and Cl can be adjusted freely within the pre-specified empirical formula.
(23) In a preferred embodiment, the preferences of the above-mentioned elements in the formula (1) or (3) apply simultaneously.
(24) The following preferably applies in formula (3): c=0, e=0 and f=0. In formula (3), d is preferably=0. In formula (3), y is preferably=0. In formula (3), b is preferably=0. In formula (3), M is preferably=Na and/or K. These preferred embodiments can be combined with one another in any desired manner.
(25) The compound (i) of the formula (1) or formula (3) preferably contains at least one of the elements M, Zr, F and/or Cl.
(26) Europium in the form of divalent Eu.sup.2+ is incorporated as dopant at the lattice site of Ba and replaces the latter.
(27) The preferred embodiments of the elements and parameters of the formula (1) or (3) can be combined with one another in any desired manner.
(28) The compounds of the formula (1) or (3) can be excited by ultraviolet and/or violet light, from preferably approximately 370 to approximately 430 nm, and have emission maxima in the green spectral region, from preferably approximately 510 to approximately 520 nm, depending on the precise composition.
(29) Particularly preferred compounds (i) of the formula (3) are compounds of the formulae (3a) and (3b):
Ba.sub.2abxSr.sub.aCa.sub.bMg.sub.1dyM.sup.2.sub.dSi.sub.2O.sub.7:Eu.sub.x,Mn.sub.y(formula (3a))
Ba.sub.2abcxSr.sub.aCa.sub.bM.sup.1.sub.cMg.sub.1ySi.sub.2O.sub.7ef+dF.sub.eCl.sub.f:Eu.sub.x,Mn.sub.y(formula (3b)) where: M.sup.1=Na and/or K; M.sup.2=Zr and/or Hf 0a1.999, more preferably 0a1.0; 0b1.999, more preferably 0b1.0; 0<c0.3, more preferably 0<c0.2; 0<d0.3; more preferably 0<d0.2; (0<e0.3 and 0f0.3) or (0e0.3 and 0<f0.3); 0.001x0.3; and 0y0.3.
(30) The following particularly preferably applies in formula (3a) and/or (3b): 0a0.6. The following most preferably applies in formula (3a) and/or (3b): a=0. The following particularly preferably applies in formula (3a) and/or (3b): 0b0.6. The following most preferably applies in formula (3a) and/or (3b): b=0.
(31) Particularly preferred compounds of the formula (3) are shown in Table 1 below.
(32) TABLE-US-00001 TABLE 1 Particularly preferred compounds of the formula (3). Emission maximum Compound Empirical formula [nm] 1 Ba.sub.1.90Eu.sub.0.10MgSi.sub.2O.sub.7 512 2 Ba.sub.1.85K.sub.0.05Eu.sub.0.10MgSi.sub.2O.sub.6.95Cl.sub.0.05 518 3 Ba.sub.1.85K.sub.0.05Eu.sub.0.10MgSi.sub.2O.sub.6.95F.sub.0.05 516 4 Ba.sub.1.90Eu.sub.0.10Mg.sub.0.95Li.sub.0.05Si.sub.2O.sub.6.95Cl.sub.0.05 513 5 Ba.sub.1.90Eu.sub.0.10Mg.sub.0.95Li.sub.0.05Si.sub.2O.sub.6.95F.sub.0.05 518 6 Ba.sub.1.90Eu.sub.0.10Mg.sub.0.95Zr.sub.0.05Si.sub.2O.sub.7.05 516
(33) In a preferred embodiment, the compound (i) of the formula (2) in the phosphor mixture according to the invention is represented by the formula (4):
(Ba,Sr,Ca).sub.advyEu.sub.dA.sub.yM.sup.1.sub.beM.sup.2.sub.eM.sup.3.sub.vO.sub.ceyN.sub.e+vX.sub.x+y(formula (4)) where: A=Na and/or K; M.sup.1=B, Al, Ga, In, Tl and/or Sc; M.sup.2=Si and/or Ge; M.sup.3=Y, Lu and/or La; X=F and/or Cl; 0.65a1.0, more preferably 0.70a0.80; 0<d1.0, more preferably 0.03d0.25, most preferably 0.05d0.20; 0y0.1.Math.a, more preferably 0y0.05.Math.a, most preferably 0 y0.03.Math.a; 10.667b11.133; 0e5.0, more preferably 0e1.0, most preferably 0e0.2; 0v0.1.Math.a, more preferably v=0; 17.00c17.35; 0x5.0; 0.0584a/b0.0938; 0.0375a/c0.0588; and 2.Math.a+3.Math.b=2.Math.c+x if v=0.
(34) The following preferably applies in formula (4): 0.0005x+y1.0, more preferably 0.001x+y0.1, most preferably 0.001x+y0.05; 0.70a0.80; 0e0.50; 0.03d0.25; 10.93b11.067; and 17.20c17.30.
(35) If the compound (i) of the formula (2) or (4) contains more than one of the elements Ba, Sr and Ca, the ratio of Ba, Sr and Ca can be adjusted freely within the pre-specified empirical formula. In a preferred embodiment, the compound (i) of the formula (2) or (4) contains 10 atom-% of Sr and/or Ca, more preferably 5 atom-% of Sr and/or Ca, and most preferably 3 atom-% of Sr and/or Ca, based on the total content of Ba, Sr and Ca. The compound (i) of the formula (2) or (4) preferably does not contain more than one of the elements Ba, Sr and Ca, particularly preferably Ba or Sr.
(36) If the compound (i) of the formula (2) or (4) contains more than one of the elements A, the ratio of Na and K can be adjusted freely within the pre-specified empirical formula. A in formulae (2) and (4) is preferably K.
(37) If the compound (i) of the formula (2) or (4) contains more than one of the elements M.sup.1, the ratio of B, Al, Ga, In, Tl and Sc can be adjusted freely within the pre-specified empirical formula. In a preferred embodiment, the compound (i) of the formula (2) or (4) contains 10 atom-% of the elements B, Ga, In, Tl and/or Sc, more preferably 5 atom-% of the elements B, Ga, In, Tl and/or Sc, and most preferably 3 atom-% of the elements B, Ga, In, Tl and/or Sc, based on the total content of all elements M.sup.1. M.sup.1 in formulae (2) and (4) is preferably Al, Ga and/or Sc, more preferably Al.
(38) If the compound (i) of the formula (2) or (4) contains more than one of the elements M.sup.2, the ratio of Si and Ge can be adjusted freely within the pre-specified empirical formula. M.sup.2 in formulae (2) and (4) is preferably Si. A trivalent element M.sup.1 and a divalent oxide anion O.sup.2 are replaced by a tetravalent element M.sup.2 and a trivalent nitride anion N.sup.3.
(39) If the compound (i) of the formula (2) or (4) contains more than one of the elements M.sup.3, the ratio of Y, Lu and La can be adjusted freely within the pre-specified empirical formula. M.sup.3 in formulae (2) and (4) is preferably La. The trivalent element M.sup.3 replaces an alkaline-earth metal element Ba, Sr and/or Ca. The charge is compensated by a trivalent nitride anion N.sup.3.
(40) If the compound (i) of the formula (2) or (4) contains more than one of the elements X, the ratio of F and Cl can be adjusted freely within the pre-specified empirical formula. X in formulae (2) and (4) is preferably F. It is either possible for a monovalent alkali metal A and a monovalent anion X to replace an alkaline-earth metal Ba, Sr and/or Ca and a divalent oxide anion O.sup.2 and/or for the charge of the monovalent anion X to be compensated by a lower content of the alkaline-earth metal Ba, Sr and/or Ca and/or for some of the divalent oxide anions O.sup.2 to be replaced by two monovalent anions X.
(41) In a preferred embodiment, the preferences of the above-mentioned elements in the formula (2) or (4) apply simultaneously.
(42) The following preferably applies in formula (2) or (4): x0 or y0 or v0 or e0, if no Ca and Sr is present and M.sup.1=Al.
(43) The preferred embodiments of the elements and parameters of the formula (2) or (4) can be combined with one another in any desired manner.
(44) The conditions indicated above for the ratio of a/b and a/c ensure that the compound is formed in the -aluminium oxide phase and arises from a -aluminium oxide structure of the composition Ba.sub.0.75Al.sub.11O.sub.17.25, as has been demonstrated by x-ray powder diffractometry. The compounds of the formula (2) or (4) exhibit a pure Ba.sub.0.75Al.sub.11O.sub.17.25 structure of -aluminium oxide, even if they contain alkali metals A or trivalent metals M.sup.3 or halide anions X or if they have been modified, for example, with Sc.sup.3+ or other trivalent cations instead of Al.sup.3+ or with Si.sup.4+ and N.sup.3 instead of Al.sup.3+ and O.sup.2. Europium in the form of divalent Eu.sup.2+ is incorporated as dopant at the lattice site of Ba and replaces the latter.
(45) The compounds of the formula (2) or (4) can be excited by ultraviolet and/or violet light, from preferably approximately 370 to approximately 430 nm, and have emission maxima in the green spectral region, from preferably approximately 510 to approximately 520 nm, depending on the precise composition.
(46) Particularly preferred compounds of the formula (4) are shown in Table 2 below.
(47) TABLE-US-00002 TABLE 2 Particularly preferred compounds of the formula (4). Emission Com- maximum pound Empirical formula [nm] 1 Ba.sub.0.69075Sr.sub.0.0225Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 515 2 Ba.sub.0.69075Ca.sub.0.0225Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 511 3 Ba.sub.0.7128Eu.sub.0.0375Al.sub.10.7753Ga.sub.0.225O.sub.17.25F.sub.0.0015 518 4 Ba.sub.0.7128Eu.sub.0.0375Al.sub.10.6253In.sub.0.375O.sub.17.25F.sub.0.0015 516 5 Ba.sub.0.73575Eu.sub.0.015Al.sub.11O.sub.17.25F.sub.0.0015 507 6 Ba.sub.0.67575Eu.sub.0.075Al.sub.11O.sub.17.25F.sub.0.0015 518 7 Ba.sub.0.71325Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 518 8 Ba.sub.0.63075Eu.sub.0.12Al.sub.11O.sub.17.25F.sub.0.0015 519 9 Ba.sub.0.63075Eu.sub.0.12Al.sub.10.8Si.sub.0.15O.sub.17.025N.sub.0.15F.sub.0.0015 521 10 Ba.sub.0.63Eu.sub.0.12075Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 517 11 Ba.sub.0.65325Eu.sub.0.075La.sub.0.0225Al.sub.11O.sub.17.2275N.sub.0.0225F.sub.0.0015 516 12 Ba.sub.0.6525Eu.sub.0.075La.sub.0.0225Al.sub.11O.sub.17.2605F.sub.0.0015 515 13 Ba.sub.0.69075Eu.sub.0.06Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 14 Ba.sub.0.66075Eu.sub.0.09Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 516 15 Ba.sub.0.63075Eu.sub.0.12Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 518 16 Ba.sub.0.6075Eu.sub.0.15Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 518 17 Ba.sub.0.57Eu.sub.0.18075Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 18 Ba.sub.0.54Eu.sub.0.21075Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 19 Ba.sub.0.69Eu.sub.0.06075Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 20 Ba.sub.0.66075Eu.sub.0.090Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 21 Ba.sub.0.63075Eu.sub.0.120Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 519 22 Ba.sub.0.6075Eu.sub.0.150Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 518 23 Ba.sub.0.57075Eu.sub.0.180Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 24 Ba.sub.0.54075Eu.sub.0.210Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 25 Ba.sub.0.63075Eu.sub.0.120Al.sub.10.5Sc.sub.0.5O.sub.17.25F.sub.0.0015 516 26 Ba.sub.0.57375Eu.sub.0.1629375K.sub.0.028125Al.sub.11O.sub.17.25F.sub.0.0015 516
(48) In a particularly preferred embodiment, the compound (i) of the formula (4) in the phosphor mixture according to the invention is represented by the formula (4a):
(Ba.sub.1zSr.sub.z).sub.adyEu.sub.dK.sub.y(Al.sub.1wSc.sub.w).sub.bO.sub.cyF.sub.x+y(formula (4a)), where: 0z0.1, more preferably 0z0.05, still more preferably 0z0.03, and most preferably z=0; 0w0.1, more preferably 0w0.05, still more preferably 0w0.03, and most preferably w=0;
(49) where the parameters a, b, c, d, x and y have the definitions described for the formula (4).
(50) In a particularly preferred alternative embodiment, the compound (i) of the formula (4) in the phosphor mixture according to the invention is represented by the formula (4b):
(Ba.sub.1zCa.sub.z).sub.adyEu.sub.dK.sub.y(Al.sub.1wSc.sub.w).sub.bO.sub.cyF.sub.x+y(formula (4b)), where: 0z0.1, more preferably 0z0.05, still more preferably 0z0.03, and most preferably z=0; 0w0.1, more preferably 0w0.05, still more preferably 0w0.03, and most preferably w=0;
(51) where the parameters a, b, c, d, x and y have the definitions described for the formula (4).
(52) In a very particularly preferred embodiment, the compound (i) of the formula (4) in the phosphor mixture according to the invention is represented by the formula (5):
Ba.sub.adyEu.sub.dK.sub.yAl.sub.bO.sub.cyF.sub.x+y(formula (5)),
(53) where the parameters a, b, c, d, x and y have the definitions described for the formula (4).
(54) In a preferred embodiment of the present invention, the phosphor mixture, besides the one or more compounds (i) of the formula (1) or (2), comprises one or more compounds (ii) selected from the group of blue- and cyan-emitting phosphors, and one or more compounds (iii) selected from the group of orange- or red-emitting phosphors.
(55) The phosphor mixture preferably comprises only in each case one compound (i) and (ii) and/or (iii).
(56) In a particularly preferred embodiment of the present invention, the phosphor mixture consists of one or more compounds (i) of the formula (1) or (2) and one or more compounds (ii) selected from the group of blue- and cyan-emitting phosphors, and one or more compounds (iii) selected from the group of orange- or red-emitting phosphors.
(57) In a very particularly preferred embodiment of the present invention, the phosphor mixture consists of one compound (i) of the formula (1) or (2) and one compound (ii) selected from the group of blue- and cyan-containing phosphors, and/or one compound (iii) selected from the group of orange- or red-emitting phosphors.
(58) The compounds (ii) are selected from the group of blue- or cyan-emitting phosphors consisting of (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+; (Sr,Ba).sub.10(PO.sub.4).sub.6Cl.sub.2:Eu; BaMgAl.sub.10O.sub.17:Eu.sup.2+; Sr.sub.4Al.sub.14O.sub.25:Eu.sup.2+; BaSi.sub.2O.sub.2N.sub.2:Eu.sup.2+; Lu.sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+; LiCaPO.sub.4:Eu.sup.2+ and mixtures thereof.
(59) The compounds (iii) are selected from the group of orange- or red-emitting phosphors consisting of (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+; (1x)(Sr,Ca)AlSiN.sub.3.x(Si.sub.2N.sub.2O):Eu.sup.2+ (where 0<x<1), in particular (Sr,Ca).sub.0.89Al.sub.0.89Si.sub.1.11N.sub.2.89O.sub.0.11:Eu.sup.2+; (Sr,Ca)AlSiN.sub.3:Eu.sup.2+; (Ca.sub.1xSr.sub.x)S:Eu.sup.2+ (where 0x1); SrLiAl.sub.3N.sub.4:Eu.sup.2+; 3.5 MgO.0.5 MgF.sub.2.GeO.sub.2:Mn.sup.4+; K.sub.2(Si,Ti)F.sub.6:Mn.sup.4+; (Ba,Sr,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+,Mn.sup.2+; Ba.sub.2(Lu,Y,Gd).sub.1xTb.sub.x(BO.sub.3).sub.2Cl:Eu.sup.2+/3+ (where 0x1); Ba.sub.2Mg(BO.sub.3).sub.2:Eu.sup.2+; La.sub.2O.sub.2S:Eu.sup.3+; (Sr,Ca,Ba).sub.2Si.sub.5N.sub.8:Eu.sup.2+; (Sr,Ca,Ba).sub.2Si.sub.5xAl.sub.xN.sub.8xO.sub.x:Eu.sup.2+ (where 0x3.0); EA.sub.dEu.sub.cE.sub.eN.sub.fO.sub.x (where EA=Ca, Sr and/or Ba; E=Si and/or Ge; 0.80d1.995; 0.005c0.2; 4.0e6.0; 5.0f8.7; 0x3.0; and 2.Math.d+2.Math.c+4.Math.e=3.Math.f+2.Math.x); A.sub.20.5yxEu.sub.xSi.sub.5N.sub.8yO.sub.y (where A=Ca, Sr and/or Ba; 0.005x1.0; and 0.1y3.0), in particular (Sr,Ba).sub.1.77Eu.sub.0.08Si.sub.5N.sub.7.7O.sub.0.3; Ma.sub.2y(Ca,Sr,Ba).sub.1xySi.sub.5zMe.sub.zN.sub.8:Eu.sub.xCe.sub.y (where Ma=Li, Na and/or K; Me=Hf.sup.4+ and/or Zr.sup.4+; 0.0015x0.20; 0y0.15; and z<4.0) and mixtures thereof.
(60) In a preferred embodiment of the present invention, conditions (A) and (B) of the phosphor mixture are defined as follows:
w(i)=40 to 95% by weight,
w(ii)=0 to 5.0% by weight and
w(iii)=5.0 to 50% by weight;(A)
w(i)=35 to 85% by weight,
w(ii)=>5.0 to 65% by weight and
w(iii)=3.5 to 45% by weight.(B)
(61) Preferred phosphor mixtures for the generation of light spectra having various melatonin suppression levels are shown in Table 3. Table 3 shows preferred phosphor mixture compositions which generate light spectra having various melatonin suppression levels in the colour temperature ranges indicated in each case on use of violet-emitting LED semiconductors as excitation light source.
(62) TABLE-US-00003 TABLE 3 Preferred phosphor mixtures with associated colour temperature and melatonin suppression ranges. Melatonin suppression level range K.sub.mel, v Colour according to temperature DIN SPEC Composition ranges range 5031-100 P1/wt.-% P2/wt.-% P3/wt.-% P4 wt.-% 2500 K-<3500 K 0-0.0005 70-95 0-5 0-20 5-30 3500 K-<4500 K 0-0.0009 60-80 0-5 0-20 5-20 4500 K-7000 K 0-0.001 35-95 0-5 0-15 5-15 2500 K-<3500 K 0.0005-0.001 45-70 10-50 0-15 5-30 3500 K-<4500 K 0.0009-0.002 40-80 5-50 0-10 0-20 4500 K-7000 K 0.001-0.002 35-85 15-65 0-10 0-20
(63) Table 4 below shows the respective individual components (phosphor components P) of the phosphor mixtures shown in Table 3.
(64) TABLE-US-00004 TABLE 4 Individual components of the phosphor mixtures shown in Table 3. Designation of the individual component Compound P1 Compounds (i) of the formulae (1), (2), (3), (3a), (3b), (4), (4a), (4b) and/or (5). P2 Compounds (ii): (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+, (Sr,Ba).sub.10(PO.sub.4).sub.6Cl.sub.2:Eu, BaMgAl.sub.10O.sub.17:Eu.sup.2+, Sr.sub.4Al.sub.14O.sub.25:Eu.sup.2+, BaSi.sub.2O.sub.2N.sub.2:Eu.sup.2+, Lu.sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+ and/or LiCaPO.sub.4:Eu.sup.2+. P3 Compound (iii): (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+. P4 Compounds (iii): (Sr,Ca).sub.0.89Al.sub.0.89Si.sub.1.11N.sub.2.89O.sub.0.11:Eu.sup.2+, (Sr,Ca)AlSiN.sub.3:Eu.sup.2+, (Sr,Ba).sub.1.77:Eu.sub.0.08Si.sub.5N.sub.7.7O.sub.0.3, (Ca.sub.1xSr.sub.x)S:Eu.sup.2+ (where 0 x 1), SrLiAl.sub.3N.sub.4:Eu.sup.2+, 3.5 MgO0.5 MgF.sub.2GeO.sub.2:Mn.sup.4+, K.sub.2(Si,Ti)F.sub.6:Mn.sup.4+, (Ba,Sr,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+, Mn.sup.2+,Ba.sub.2(Lu,Y,Gd).sub.1xTb.sub.x(BO.sub.3).sub.2Cl:Eu.sup.2+/3+ (where 0 x 1), Ba.sub.2Mg(BO.sub.3).sub.2:Eu.sup.2+, La.sub.2O.sub.2S:Eu.sup.3+, (Sr,Ca,Ba).sub.2Si.sub.5N.sub.8:Eu.sup.2+ and/or (Sr,Ca,Ba).sub.2Si.sub.5xAl.sub.xN.sub.8xO.sub.x:Eu.sup.2+ (where 0 x 3.0).
(65) For use in light-emitting devices, in particular in LEDs, the phosphor mixture according to the invention can be converted into any desired outer shapes, such as, for example, spherical particles, flakes and structured materials and ceramics. These shapes are summarised in accordance with the invention under the term shaped bodies. The shaped body is preferably a phosphor body. The present invention thus furthermore relates to a shaped body comprising the phosphors according to the invention. The production and use of corresponding shaped bodies is familiar to the person skilled in the art from numerous publications.
(66) Besides the phosphor mixtures according to the invention, ceramics comprise matrix materials, such as, for example, silazane compounds, in particular polysilazanes or polysiloxazanes. Particularly preferred matrix materials are perhydropolysilazane (PHPS), Al.sub.2O.sub.3, Y.sub.3Al.sub.5O.sub.12, SiO.sub.2, Lu.sub.3Al.sub.5O.sub.12, Al.sub.2W.sub.3O.sub.12, Y.sub.2W.sub.3O.sub.12, YAlW.sub.3O.sub.12, ZrW.sub.2O.sub.8, Al.sub.2Mo.sub.3O.sub.12, Y.sub.2Mo.sub.3O.sub.12, YAlMo.sub.3O.sub.12, ZrMo.sub.2O.sub.8, Al.sub.2WMo.sub.2O.sub.12, Y.sub.2WMo.sub.2O.sub.12, YAlWMo.sub.2O.sub.12, ZrWMoO.sub.8, Al.sub.2MoW.sub.2O.sub.12, Y.sub.2MoW.sub.2O.sub.12, YAlMoW.sub.2O.sub.12 or mixtures thereof.
(67) Likewise suitable matrix materials are magnesium aluminium spinel, yttrium oxide, aluminium oxynitride, zinc sulfide, zirconium oxide, yttrium lanthanum oxide, strontium chromate, magnesium oxide, beryllium oxide, yttrium oxide/zirconium dioxide, gallium arsenide, zinc selenide, magnesium fluoride, calcium fluoride, scandium oxide, lutetium oxide and gadolinium oxide.
(68) In addition, the phosphor mixtures according to the invention may also be provided as so-called phosphor in glass applications (PIGs), as described, for example, in WO 2013/144777 A1.
(69) Process for the preparation of the phosphor mixture
(70) The process according to the invention for the preparation of a phosphor mixture, as described above, comprises the following steps:
(71) a) weighing-out of a weight m(i) of phosphor (i), a weight m(ii) of phosphor (ii) and/or a weight m(iii) of phosphor (iii); and
(72) b) mixing of the weights of phosphors (i), (ii) and/or (iii) weighed out in step a).
(73) The weighing-out of the weights m(i), m(ii) and/or m(iii) in step a) is preferably carried out successively. In a particular embodiment, the weighing-out may also be carried out simultaneously.
(74) The mixing in step b) is preferably carried out with the aid of a planetary centrifugal mixer, a roller bench, an overhead mixer, a tumble mixer, a star-wheel mixer, a ball mill, a mortar mill or a fluidised-bed mixer. The mixing operation can be carried out here both in the wet state (i.e. the materials to be mixed are introduced into a suitable liquid, such as, for example, water or ethanol, before the mixing) or in the dry state.
(75) Steps a) and b) are preferably carried out at room temperature, more preferably at 20 to 25 C.
(76) Light-Emitting Device
(77) The light-emitting device according to the invention comprises at least one primary light source and at least one phosphor mixture, as described above.
(78) The primary light source is preferably either a semiconductor light-emitting diode (SLED), a semiconductor laser diode (LD) or an organic light-emitting diode (OLED). In an alternative preferred embodiment, the primary light source of the light-emitting device can be a plasma or discharge source. Preference is given to primary light sources which emit light in the spectral region from approximately 385 to approximately 480 nm, more preferably from approximately 390 to approximately 450 nm and most preferably from approximately 395 to 440 nm.
(79) A semiconductor light-emitting diode (SLED), which forms a first group of suitable primary light sources, is a two-lead semiconductor light source. It is a p-n junction diode which emits light on activation. If a suitable voltage is applied to the supply lines, electrons are able to recombine with electron holes inside the device, causing energy to be released in the form of photons. This effect is called electroluminescence, and the colour of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor. The structure and mode of functioning of an SLED are known to the person skilled in the art.
(80) In a preferred embodiment, the primary light source is an SLED which comprises a luminescent indium aluminium gallium nitride, preferably of the formula In.sub.iGa.sub.jAl.sub.kN (where 0i, 0j, 0k and i+j+k=1), or a luminescent arrangement based on ZnO, a transparent conducting oxide (TCO), ZnSe or SiC.
(81) A semiconductor laser diode (LD), also known as injection laser diode or ILD, is an electrically pumped semiconductor laser in which the active laser medium is formed by a p-n junction of a semiconductor diode, in a similar way to in an SLED. The structure and mode of functioning of an LD are known to the person skilled in the art. The LD is the most widespread type of a laser which is produced for manifold applications, such as, for example, glass fibre communications, barcode readers, laser pointers, CD, DVD and Blu-ray disc readers and recorders or the like, laser printers, laser scanners and increasingly directed light sources.
(82) A third group of suitable primary light sources comprises so-called organic light-emitting diodes (OLEDs), in which the emitting electroluminescent layer is a film of an organic compound which emits light in reaction to an electric current. This layer of an organic semiconductor is located between two electrodes. Typically, at least one of these electrodes is transparent. The structure and mode of functioning of OLEDs are known to the person skilled in the art
(83) The light-emitting device is preferably a light-emitting diode (LED).
(84) Lighting System
(85) The lighting system according to the invention comprises at least two light-emitting devices, preferably LEDs, where the at least two light-emitting devices emit light having an identical colour location and/or an identical colour rendering index and/or an identical correlated colour temperature and where the light from the at least two light-emitting devices differs from one another with respect to the spectral composition, characterised in that each of the at least two light-emitting devices comprises at least two different phosphors, where at least one of the phosphors can be excited by violet light and optionally by ultraviolet light and has a relative excitability at 450 nm of 65%, preferably 60%, furthermore preferably 55%, more preferably 40% and most preferably 30%, and where the maximum excitability in the excitation spectrum corresponds to 100%.
(86) The light from the at least two light-emitting devices differs with respect to the spectral composition if at least one parameter coupled to the spectral emission profile, such as, for example, the colour location, the colour rendering, the correlated colour temperature or the melatonin suppression, of the first light-emitting device differs from the corresponding parameter of the second light-emitting device.
(87) Differ in this context means that (1) In the case of the colour location, the value of the difference between the x colour coordinates of the colour locations of the various light-emitting devices to be compared in the CIE-1931 standard valency system (2 standard observer) is >0.007; this also applies to the value of the difference between the y colour coordinates (valid in the same colour system) of the colour locations to be compared; (2) in the case of the general colour rendering index Ra (determined in accordance with CIE 13.3-1995), the relative difference between the general colour rendering indices in the comparison of the light-emitting devices is >7%; (3) in the case of the correlated colour temperature (in K), the relative difference between the correlated colour temperatures in the comparison of the light-emitting devices is >10%; (4) in the case of the melatonin suppression level K.sub.mel,v (determined in accordance with DIN SPEC 5031-100), the relative difference between the melatonin suppression levels in the comparison of the light-emitting devices is >5%; and (5) in the case of further parameters not explicitly mentioned here, the relative difference between these parameters in the comparison of the light-emitting devices is >10%, preferably >7%, more preferably >5%.
(88) In a preferred embodiment of the present invention, the at least two light-emitting devices in the lighting system are light-emitting devices according to the invention, as described above.
(89) The lighting system of the present invention is preferably a dynamic lighting system.
(90) The present invention furthermore relates to a dynamic lighting system which comprises at least two light-emitting devices according to the invention, where the at least two light-emitting devices according to the invention emit light having an identical colour location and/or an identical colour rendering index and/or an identical correlated colour temperature, characterised in that the light from the at least two light-emitting devices according to the invention differs from one another with respect to the spectral composition.
(91) The light from the at least two light-emitting devices according to the invention in the dynamic lighting system differs with respect to the spectral composition if at least one parameter coupled to the spectral emission profile, such as, for example, the colour location, the colour rendering, the correlated colour temperature or the melatonin suppression, of the first light-emitting device according to the invention differs from the corresponding parameter of the second light-emitting device according to the invention, as defined above.
(92) Use
(93) The phosphor mixtures according to the invention can be used in a light-emitting device for the conversion of blue, violet and/or ultraviolet radiation into light having a longer wavelength.
(94) The light-emitting device is preferably a light-emitting diode (LED) for use in general lighting and/or in specialty lighting.
(95) The phosphor mixtures according to the invention give rise to good LED qualities even when employed in small amounts. The LED quality is described here by means of conventional parameters, such as, for example, the colour rendering index, the correlated colour temperature, the lumen equivalent or absolute lumens or the colour location in CIE x and y coordinates.
(96) The colour rendering index (CRI) is a dimensionless lighting quantity, familiar to the person skilled in the art, which compares the colour reproduction faithfulness of an artificial light source with the colour reproduction faithfulness of pre-specified reference light sources (the reference light sources have a CRI of 100; the precise definition of the CRI is given in CIE publication 13.3-1995).
(97) The correlated colour temperature (CCT) is a lighting quantity, familiar to the person skilled in the art, with the unit kelvin. The higher the numerical value, the higher the blue content of the light and the colder the white light from an artificial radiation source appears to the observer. The CCT follows the concept of the black body radiator, whose colour temperature describes the so-called Planck curve in the CIE diagram.
(98) The lumen equivalent is a lighting quantity, familiar to the person skilled in the art, with the unit Im/W which describes the magnitude of the photometric luminous flux in lumens of a light source at a certain radiometric radiation power with the unit watt. The higher the lumen equivalent, the more efficient a light source.
(99) The lumen is a photometric lighting quantity, familiar to the person skilled in the art, which describes the luminous flux of a light source, which is a mea-sure of the total visible radiation emitted by a radiation source. The greater the luminous flux, the brighter the light source appears to the observer.
(100) CIE x and CIE y stand for the coordinates in the standard CIE colour chart (here standard observer 1931), familiar to the person skilled in the art, by means of which the colour of a light source is described.
(101) All the parameters mentioned above can be calculated from the emission spectra of the light source using methods known to the person skilled in the art.
(102) All variants of the invention that are described here can be combined with one another so long as the respective embodiments are not mutually exclusive. In particular, on the basis of the teaching of this specification, it is an obvious operation, as part of routine optimisation, precisely to combine various variants described here in order to arrive at a specific particularly preferred variants. The following examples are intended to illustrate the present invention and show, in particular, the result of such illustrative combinations of the described variants of the invention. However, they should in no way be regarded as limiting, but instead are intended to prompt generalisation. All compounds or components used in the preparations are either known and commercially available or can be synthesised by known methods. The temperatures indicated in the examples are always in C. It furthermore goes without saying that, both in the description and also in the examples, the amounts of the constituents used in the compositions always add up to a total of 100%. Percent data should always be viewed in the given context.
EXAMPLES
(103) Examples of phosphor mixtures according to the invention
(104) General procedure for the construction and measurement of phosphor-converted LEDs
(105) A weight m.sub.P1 (in g) of phosphor component 1 indicated in the respective LED example is weighed out together with m.sub.P2 (in g) of phosphor component 2 indicated in the respective LED example, with m.sub.P3 (in g) of phosphor component 3 indicated in the respective LED example and with m.sub.P4 (in g) of phosphor component 4 indicated in the respective LED example and mixed homogeneously in a planetary centrifugal mixer.
(106) An optically transparent Binder (for example silicone) is subsequently added to the mixture and incorporated so that the phosphor concentration in the optically transparent Binder is expressed by Cp (in wt. %). The binder/phosphor mixture obtained in this way is applied to the chip of a violet-emitting semiconductor LED with the aid of an automatic dispenser and cured with supply of heat.
(107) The violet-emitting semiconductor LEDs used in the present examples for LED characterisation have emission wavelengths in the range 405 nm 415 nm and are operated with a current strength of 350 mA.
(108) The photometric characterisation of the LED is carried out using an Instrument Systems CAS 140 spectrometer and ISP 250 integration sphere connected thereto. The LED is characterised by determination of the wavelength-dependent spectral power density. The resultant spectrum of the light emitted by the LED is used to calculate the CIE x and y colour point coordinates, the correlated colour temperature (CCT) and, if necessary, the brightness or melanopic yield of visible radiation K.sub.mel,v in accordance with DIN SPEC 5031-100.
(109) Table 5 shows LED Examples 1 and 2 of an LED emitting cold-white light with non-reabsorbable blue and green phosphors or a reabsorbable green phosphor.
(110) TABLE-US-00005 TABLE 5 LED Examples 1 and 2 with phosphor mixtures comprising non- reabsorbable or reabsorbable phosphor mixture components. LED Example 1 LED Example 2 LED emitting LED emitting cold-white light cold-white light with non-reabsorbable with reabsorbable blue and green phosphors green phosphor P1 Green-emitting phosphor in Green-emitting phosphor in accordance with compound (i) accordance with compound (i) of the composition of the composition Ba.sub.2xEu.sub.xMg.sub.1yzZr.sub.yMn.sub.zSi.sub.2O.sub.7+y Si.sub.6zAl.sub.zO.sub.zN.sub.8z:Eu.sup.2+ where 0.001 x 0.3; where 0 < z < 4.2 0.01 y 0.3; and 0 z 0.3 P2 Blue-emitting phosphor in Blue-emitting phosphor in accordance with compound (ii) accordance with compound of the composition (ii) of the composition (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+ (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+ P3 P4 Red-emitting phosphor in Red-emitting phosphor in accordance with compound accordance with compound (iii) of the composition (iii) of the composition (Sr,Ca).sub.0.89Al.sub.0.89Si.sub.1.11N.sub.2.89O.sub.0.11:Eu.sup.2+ (Sr,Ca).sub.0.89Al.sub.0.89Si.sub.1.11 N.sub.2.89O.sub.0.11:Eu.sup.2+ m.sub.P1/g: 0.9787 0.1885 m.sub.P2/g: 0.9213 1.4231 m.sub.P3/g: m.sub.P4/g: 0.4000 0.4884 c.sub.P/wt.-%: 23 21 CIE (1931) x: 0.376 0.376 CIE (1931) y: 0.374 0.375 CCT/K: 5058 4907 Brightness/lm 55 51
(111) LED Examples 1 and 2 show a non-reabsorbable system compared with a reabsorbable system, for which the improvement in the overall efficiency can be demonstrated.
(112) Table 6 shows LED Examples 3 and 4 of an LED emitting neutral-white light having a low melatonin suppression level and a high melatonin suppression level respectively.
(113) TABLE-US-00006 TABLE 6 LED Examples 3 and 4 with phosphor mixtures having a high and low melatonin suppression level respectively. LED Example 3 LED Example 4 LED emitting LED emitting neutral-white neutral-white light having a light having a low melatonin high melatonin suppression level suppression level P1 Green-emitting phosphor in Green-emitting phosphor in accordance with compound (i) accordance with compound (i) of the composition of the composition Ba.sub.2xEu.sub.xMg.sub.1yzZr.sub.yMn.sub.zSi.sub.2O.sub.7+y Ba.sub.2xEu.sub.xMg.sub.1yzZr.sub.yMn.sub.zSi.sub.2O.sub.7+y where 0.001 x 0.3; where 0.001 x 0.3; 0.01 y 0.3; and 0.01 y 0.3; and 0 z 0.3 0 z 0.3 P2 Blue-emitting phosphor in accordance with compound (ii) of the composition (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+ P3 Orange-emitting phosphor in Orange-emitting phosphor in accordance with compound accordance with compound (iii) of the composition (iii) of the composition (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+ (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+ P4 Red-emitting phosphor in Red-emitting phosphor in accordance with compound accordance with compound (iii) of the composition (iii) of the composition (Sr,Ca)AlSiN.sub.3:Eu.sup.2+ (Sr,Ca)AlSiN.sub.3:Eu.sup.2+ m.sub.P1/g: 1.2944 2.3108 m.sub.P2/g: 1.6159 m.sub.P3/g: 0.2367 0.2081 m.sub.P4/g: 0.2689 0.3651 c.sub.P/wt.-%: 18 45 CIE (1931) x: 0.376 0.376 CIE (1931) y: 0.374 0.375 CCT/K: 4113 4113 K.sub.mel, v 0.0008 0.0010
(114) LED Examples 3 and 4 show two LED spectra which, with a virtually identical colour location, have different melatonin suppression levels and which can therefore be combined with one another in the manner described here in a 2-channel lighting system.
(115) Table 7 shows LED Examples 5 and 6 of an LED emitting neutral-white light having a low melatonin suppression level and a high melatonin suppression level respectively.
(116) TABLE-US-00007 TABLE 7 LED Example 5 and 6 with phosphor mixtures having a high and low melatonin suppression level respectively. LED Example 5 LED Example 6 LED emitting LED emitting neutral-white neutral-white light having a light having a low melatonin high melatonin suppression level suppression level P1 Green-emitting phosphor in Green-emitting phosphor in accordance with compound accordance with compound (i) (i) of the composition of the composition Ba.sub.0.63075Eu.sub.0.12Al.sub.11O.sub.17.25F.sub.0.0015 Ba.sub.0.63075Eu.sub.0.12Al.sub.11O.sub.17.25F.sub.0.0015 (cf. Table 2, compound 8) (cf. Table 2, compound 8) P2 Blue-emitting phosphor in accordance with compound (ii) of the composition (Sr,Ba,Ca).sub.3MgSi.sub.2O.sub.8:Eu.sup.2+ P3 Orange-emitting phosphor in Orange-emitting phosphor in accordance with compound accordance with compound (iii) of the composition (iii) of the composition (Sr,Ba).sub.3SiO.sub.5:Eu.sup.2+ (Sr,Ba).sub.3SiO.sub.5Eu.sup.2+ P4 Red-emitting phosphor in Red-emitting phosphor in accordance with compound accordance with compound (iii) of the composition (iii) of the composition (Sr,Ca)AlSiN.sub.3:Eu.sup.2+ (Sr,Ca)AlSiN.sub.3:Eu.sup.2+ m.sub.P1/g: 2.7778 4.5212 m.sub.P2/g: 0.9585 m.sub.P3/g: 0.0370 0.0801 m.sub.P4/g: 0.1852 0.1602 c.sub.P/wt.-%: 30 57 CIE (1931) x: 0.376 0.381 CIE (1931) y: 0.374 0.371 CCT/K: 4113 3947 K.sub.mel, v 0.0009 0.0010
(117) LED Examples 5 and 6 show two LED spectra which, with a virtually identical colour location, have different melatonin suppression levels and which can therefore be combined with one another in the manner described here in a 2-channel lighting system.