LUMINOPHORE, LUMINOPHORE MIXTURE, METHOD FOR PRODUCING A LUMINOPHORE AND RADIATION-EMITTING COMPONENT

Abstract

A luminophore with the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu is provided, where 0b1, 0<x1 and 0y1. A luminophore mixture containing at least two luminophores selected from the group consisting of a luminophore (1) having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, which crystallizes in a triclinic crystal structure, a luminophore (1) having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b 1, 0<x1 and 0y1, which crystallizes in a monoclinic crystal structure, and a luminophore (1) having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, which crystallizes in a tetragonal crystal structure is also provided.

Claims

1. A luminophore with the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1.

2. The luminophore according to claim 1, which crystallizes in a triclinic crystal structure.

3. The luminophore according to claim 1, which crystallizes in a monoclinic crystal structure.

4. The luminophore according to claim 1, which crystallizes in a tetragonal crystal structure.

5. The luminophore according to claim 1, which has an absorption spectrum which has an absorption maximum in a range from 400 nm to 500 nm.

6. The luminophore according to claim 1, which has an emission spectrum comprising at least one emission peak at a wavelength in a range from 510 nm to 580 nm.

7. The luminophore according to claim 6, wherein the emission spectrum has a dominant wavelength selected from a range of 540 nm to 580 nm.

8. The luminophore according to claim 6, wherein the at least one emission peak has a full width at half maximum that is less than 75 nm.

9. The luminophore according to claim 1, wherein Eu has a concentration of up to and including 10 mol % with respect to the total content of Sr and Ba.

10. The luminophore according to claim 1, comprising one of the compositions Sr.sub.1Li.sub.3Ga.sub.1O.sub.4:Eu Sr.sub.1Li.sub.3Ga.sub.1O.sub.3,75N.sub.0,25:Eu Sr.sub.1Li.sub.3Al.sub.0,8Ga.sub.0,2O.sub.3,75N.sub.0,25:Eu Sr.sub.1Li.sub.3Al.sub.0,8Ga.sub.0,2O.sub.4:Eu Sr.sub.0,6Ba.sub.0,4Li.sub.3Ga.sub.1O.sub.4:Eu Sr.sub.0,5Ba.sub.0,5Li.sub.3Al.sub.0,5Ga.sub.0,5O.sub.3,75N.sub.0,25:Eu.

11. A luminophore mixture containing at least two luminophores selected from the group consisting of a luminophore having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, which crystallizes in a triclinic crystal structure, a luminophore having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, which crystallizes in a monoclinic crystal structure, and a luminophore having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, which crystallizes in a tetragonal crystal structure.

12. A method for producing a luminophore having the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, where 0b1, 0<x1 and 0y1, comprising: providing a mixture of reactants selected from a group comprising oxides, nitrides, carbonates, nitrates, oxalates, citrates and hydroxides of Sr, Ba, Li, Al and Ga, respectively, and combinations thereof, homogeneously mixing the reactants, heating the reactants to a temperature selected from a range of 600 C. to 1000 C.

13. The method according to claim 12, wherein the temperature is selected from a range of 750 C. to 850 C.

14. The method according to claim 12, wherein the reactants are selected from at least one of the group of SrO, BaO, BaGa.sub.2O.sub.4, Ga.sub.2O.sub.3, Li.sub.2O, SrAl.sub.2O.sub.4, SrGa.sub.2O.sub.4, GaN, Sr.sub.3Al.sub.2N.sub.4 and Eu.sub.2O.sub.3.

15. The method according to claim 12, wherein the heating is carried out in a forming gas atmosphere.

16. The method according to claim 12, wherein the heating is carried out for a period of from 2.5 hours to 6 hours.

17. The method according to claim 12, wherein the heating is carried out at normal pressure.

18. A radiation-emitting component comprising: a semiconductor chip which, in operation, emits electromagnetic radiation of a first wavelength range from a radiation exit surface, and a conversion element on the radiation exit surface, which comprises a luminophore according to claim 1, which converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, or a luminophore mixture according to claim 11, which converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range.

19. The radiation-emitting component according to the claim 18, which is free of a further luminophore.

20. The radiation-emitting component according to claim 18, wherein at least one further luminophore is present in the conversion element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Further embodiments or aspects of the present disclosure will described below in conjunction with the following drawings, wherein:

[0070] FIG. 1 shows a schematic sectional view of a radiation-emitting component according to an exemplary embodiment of the present disclosure.

[0071] FIG. 2 shows a schematic sectional view of a radiation-emitting component according to an exemplary embodiment of the present disclosure.

[0072] FIG. 3 shows the crystal structure of a luminophore according to an exemplary embodiment of the present disclosure.

[0073] FIG. 4 shows the crystal structure of a luminophore according to an exemplary embodiment of the present disclosure.

[0074] FIGS. 5A to 5F show emission spectra of luminophores according to various exemplary embodiments of the present disclosure.

[0075] FIG. 6 shows emission spectra of luminophores according to various exemplary embodiments of the present disclosure.

[0076] FIG. 7 shows a split emission spectrum of a luminophore according to an exemplary embodiment of the present disclosure.

[0077] FIGS. 8A and 8B show emission spectra of luminophores according to exemplary embodiments of the present disclosure in comparison to comparative examples.

[0078] FIG. 9 shows calculated powder diffractograms.

[0079] FIG. 10 shows the crystal structure of a luminophore according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

[0080] Elements that are identical, similar or have the same effect are marked with the same reference signs in the figures. The figures and the proportions of the elements shown in the figures should not be considered to be to scale. Rather, individual elements, in particular layer thicknesses, may be shown in exaggerated size for better visualization and/or understanding.

[0081] FIG. 1 shows a schematic sectional view of a radiation-emitting component according to an exemplary embodiment. The radiation-emitting component 100 has a semiconductor chip 10. During operation, the semiconductor chip 10 emits electromagnetic radiation of a first wavelength range (primary radiation) from a radiation exit surface 11. The semiconductor chip 10 has an epitaxially grown semiconductor layer sequence with an active zone 12, which is suitable for generating electromagnetic radiation. The primary radiation has wavelengths in the blue and/or ultraviolet range, for example.

[0082] Furthermore, the component has a conversion element 20. The conversion element 20 either contains a matrix in which the luminophore 1, in particular particles of the luminophore 1, is embedded in, or the conversion element 20 has or consists of a ceramic formed from the luminophore 1. Alternatively, the conversion element 20 contains a matrix in which a luminophore mixture 1, in particular particles of the luminophore mixture 1, is embedded, or the conversion element 20 has or consists of a ceramic formed from the luminophore mixture 1.

[0083] The luminophore 1 or the luminophore mixture 1 has the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu, wherein 0b1, 0<x 1 and 0y1. According to embodiments, the luminophore 1 or the luminophore mixture 1 is embodiments A1 to A6, which are given in Table 1:

TABLE-US-00001 TABLE 1 Exemplary embodiment Composition A1 Sr.sub.1Li.sub.3Ga.sub.1O.sub.3.75N.sub.0.25:Eu A2 Sr.sub.1Li.sub.3Ga.sub.1O.sub.4:Eu A3 Sr.sub.1Li.sub.3Al.sub.0.8Ga.sub.0.2O.sub.3.75N.sub.0.25:Eu A4 Sr.sub.1Li.sub.3Al.sub.0.8Ga.sub.0.2O.sub.4:Eu A5 Sr.sub.0.6Ba.sub.0.4Li.sub.3Ga.sub.1O.sub.4:Eu A6 Sr.sub.0.5Ba.sub.0.5Li.sub.3Al.sub.0.5Ga.sub.0.5O.sub.3.75N.sub.0.25:Eu

[0084] If the luminophore 1 is, for example, one of these embodiments or any other composition within the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu with 0b1, 0<x 1 and 0y1, and crystallize either in the triclinic space group P1, in the monoclinic space group C2/m or in the tetragonal space group I4/m. The luminophore 1 therefore only crystallizes in one crystal structure.

[0085] In the case of the luminophore mixture 1, it may, for example, comprise two or three luminophores which independently of one another comprise one of the embodiments A1 to A6 or any other composition within the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu with 0b1, 0<x1 and 0y1, wherein each luminophore in the luminophore mixture 1 has a different crystal structure, so that two or three different crystal structures are present in the luminophore mixture 1. The crystal structures are selected from the triclinic space group P1 the monoclinic space group C2/m and the tetragonal space group I4/m. The luminophore mixture 1 thus has several phases which differ from one another at least in their crystal structures, and possibly also in the exact composition of the luminophores.

[0086] In addition, at least one further luminophore may be present in the conversion element 20, which forms a mixture of luminophores with the luminophore 1 or the luminophore mixture 1 described herein.

[0087] If the conversion element 20 has a matrix in which the luminophore 1, the luminophore mixture 1 or optionally the mixture of luminophores is embedded, the matrix has a material selected from polymers such as polystyrene, polysiloxane, polysilazane, PMMA, polycarbonate, polyacrylate, polytetrafluoroethylene, polyvinyl, silicone resin, silicone, epoxy resin and transparent synthetic rubber, and glass such as silicates, water glass and quartz glass.

[0088] During operation, the luminophore 1 or the luminophore mixture 1 converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of the second wavelength range (secondary radiation). In exemplary embodiments A1 to A6, the secondary radiation is in the yellow to yellow-green range, in particular when excited with primary radiation in the blue or UV range. If the primary radiation is not completely converted by the conversion element, the component thus emits mixed light, which is composed of primary and secondary radiation and, if further luminophores are present in the conversion element 20, the emitted radiation of these further luminophores. Such a component 100 emits white light, for example.

[0089] The conversion element 20, which is designed here as a conversion layer, can either be applied directly to the semiconductor chip 10 or attached to it, for example by means of an adhesive layer (not explicitly shown here). It is also conceivable to form it as a luminophore wheel.

[0090] The semiconductor chip 10 with the conversion element 20 arranged thereon is arranged in the recess of a housing 30. The housing 30 has side surfaces which are beveled towards the semiconductor chip 10 and can be reflective. The semiconductor chip 10 and the conversion element 20 may be surrounded by a potting 40 in the housing 30, as shown here. However, the presence of a potting 40 is not absolutely necessary. The potting can be formed from a silicone or epoxy resin, for example, and has a transmittance for electromagnetic radiation of the active zone 12 that is at least 85%, e.g., 95%.

[0091] Alternatively, the housing 30 can also have no side walls and thus no recess and be designed as a carrier (not shown here).

[0092] FIG. 2 shows another exemplary embodiment of a radiation-emitting component. The explanations made with reference to FIG. 1 apply to the elements with the same reference signs. In this exemplary embodiment, the conversion element 20 is not arranged directly on the semiconductor chip 10, but spaced from it on the side of the potting 40 facing away from the semiconductor chip 10. Here too, the conversion element 20 is again formed as a conversion layer.

[0093] The components shown in FIGS. 1 and 2 are LEDs, for example. For the sake of clarity, additional elements, such as electrical contacts, are not shown in FIGS. 1 and 2. In the following, the method for producing the luminophore 1 is explained with reference to exemplary embodiments A1 to A6. The following explanations apply analogously to the luminophore mixture 1, provided that the luminophore mixture 1 comprises different luminophores of the same composition with different crystal structures.

[0094] Table 2 shows the reactants used for the preparation of exemplary embodiments A1 to A6 and the respective weights in g. These are weights for theoretical compounds that do not necessarily correspond to the resulting end product due to charge neutrality.

TABLE-US-00002 TABLE 2 SrO Li.sub.2O SrAl.sub.2O.sub.4 SrGa.sub.2O.sub.4 GaN Sr.sub.3Al.sub.2N.sub.4 BaGa.sub.2O.sub.4 Eu.sub.2O.sub.3 BaO Ga.sub.2O.sub.3 A1 8.47 3.66 0 0 0.68 0 0 0.29 0 6.89 A2 2.1 1.82 0 5.92 0 0 0 0.14 0 0 A3 3.96 4.28 6.87 2.78 0 1.78 0 0.34 0 0 A4 2.45 2.12 3.89 1.38 0 0 0 0.17 0 0 A5 1.17 1.52 0 1.02 0 0 5.77 0.12 2.15 0 A6 0.21 1.81 1.664 1.178 0 0.7542 2.068 0.142 2.171 0

[0095] To produce the respective luminophores 1 or luminophore mixtures 1, a flux can also be added to the reaction mixture. The flux is, for example, Li.sub.2BO.sub.4, of which 0.3 g (in exemplary embodiments A2 and A6) or 0.6 g (in exemplary embodiments A1 and A3 to A5) is added to the reaction mixture.

[0096] For the synthesis, stoichiometric mixtures are prepared from the respective reactants, mixed homogeneously and then heated. Heating takes place in nickel crucibles in a chamber furnace under a forming gas atmosphere (91% N.sub.2/9% H.sub.2) at 800 C. for 4 hours. The reactants are reacted and the resulting products contain the respective luminophore 1 or the luminophore mixture 1.

[0097] The structures of the exemplary embodiments are characterized by means of single crystal X-ray diffraction. The lattice parameters, crystallographic data and the basic quality parameters of the X-ray diffraction determination of exemplary embodiment A2 are shown in Table 3. In the table, another example is given in the right-hand column, which can be used to show that Al and Ga can be exchanged within the general formula of the luminophore:

TABLE-US-00003 TABLE 3 Total formula Sr[Li.sub.3GaO.sub.4]:Eu.sup.2+ Sr[Li.sub.3Al.sub.0.25Ga.sub.0.75O.sub.4]:Eu.sup.2+ Formula mass/g 242.16 231.59 mol.sup.1 Z 4 4 Structure type Sr[LiAl.sub.3N.sub.4] Sr[LiAl.sub.3N.sub.4] Crystal system triclinic triclinic Room group P1 P1 Grid parameters a 581.4(2) pm a 581.0(1) pm b 737.5(2) pm b 737.6(2) pm c 979.3(2) pm c 978.9(2) pm 84.186(8) 84.106(5) 76.759(8) 76.740(5) 79.656(7) 79.531(6) Volume V 0.4013(2) nm.sup.3 0.4007(2) nm.sup.3 Crystallographic 4.008 3.839 density /g cm.sup.3 T/K 296 296 Diffractometer BRUKER D8 Quest BRUKER D8 Quest Radiation Cu K.sub. (154.178 nm) Cu K.sub. (154.178 nm) Measuring range 4.65 64.19 4.65 42.35 Measured/ 1117/911 537/401 independent reflexes Measured reciprocal 6 h 6; 4 h 4; space 8 k 8; 6 k 6; 0 l 11 8 l 8 R.sub.all/wR.sub.ref 8.17%/18.97% 7.09%/11.46% GoF 1.182 1.044

[0098] The crystallographic positional parameters of the refined structure of exemplary embodiment A2 are summarized in Table 4:

TABLE-US-00004 TABLE 4 Atomic Wyckoff Name type location x y z Occupation U.sub.iso Sr01 Sr 2i 0.0097(7) 0.6221(4) 0.1177(4) 1 0.0123(15) Sr02 Sr 2i 0.9741(9) 0.8671(5) 0.3768(4) 1 0.0120(14) Ga03 Al 2i 0.4630(10) 0.7938(8) 0.1321(7) 1 0.0090(17) Ga04 Al 2i 1.1671(9) 0.6932(8) 0.6542(8) 1 0.0081(17) O005 O 2i 1.347(6) 0.842(5) 0.529(4) 1 0.014(7) O006 O 2i 0.653(6) 0.889(5) 0.226(4) 1 0.016(7) O007 O 2i 0.651(5) 0.657(4) 0.009(4) 1 0.010(7) O008 O 2i 1.166(5) 0.458(4) 0.602(4) 1 0.012(7) O009 O 2i 0.332(6) 0.613(5) 0.262(4) 1 0.014(7) O00A O 2i 0.860(5) 0.814(4) 0.643(4) 1 0.010(6) O00B O 2i 1.155(5) 0.692(4) 0.842(4) 1 0.009(6) O00C O 2i 0.177(5) 0.930(4) 0.097(4) 1 0.011(6) Li06 Li 2i 0.543(16) 0.948(13) 0.387(12) 1 0.02(2) Li05 Li 2i 1.476(13) 0.313(11) 0.626(10) 1 0.010(18) Li04 Li 2i 0.813(14) 0.820(12) 0.148(12) 1 0.014(19) Li03 Li 2i 0.190(16) 0.444(13) 0.404(13) 1 0.02(2) Li02 Li 2i 0.474(13) 0.568(10) 0.123(9) 1 0.005(16) Li01 Li 2i 1.171(14) 0.942(13) 0.093(12) 1 0.014(19)

[0099] FIG. 3 schematically shows the crystal structure of the luminophore 1, which has a triclinic crystal structure. The structure is isotypical of that of the already known Sr[LiAl.sub.3 N.sub.4]:Eu (described in Pust, P. et al., Nat. Mater., 13, 891-896 (2014)). In FIG. 3, hatched circles represent Sr or Ba, closely hatched tetrahedra represent LiO.sub.4 tetrahedra and widely hatched tetrahedra represent (Al,Ga)O.sub.4 tetrahedra. The tetrahedra each have common edges and/or corners. LiO.sub.4 tetrahedra can also be linked to each other via common edges, while GaO.sub.4 tetrahedra are not. The tetrahedra are each spanned by four oxygen atoms or by three oxygen atoms and one nitrogen atom or by two oxygen atoms and two nitrogen atoms or by one oxygen atom and three nitrogen atoms, or by four nitrogen atoms. Li or Ga or Al are arranged in the resulting tetrahedral gaps. Sr or Ba, which are eightfold coordinated, is arranged in channels formed by the tetrahedra. Free channels are also present.

[0100] Table 5 shows the most important crystallographic data of the exemplary embodiments A1 to A6, which crystallize in the triclinic crystal structure, obtained from X-ray powder diffraction data:

TABLE-US-00005 TABLE 5 Volume [nm].sup.3 a [pm] b [pm] c [pm] [] [] [ ] A1 0.4025 582.0 738.5 980.0 84.195 76.770 79.610 A2 0.4028 582.1 738.7 980.4 84.176 76.758 79.603 A3 0.3925 575.9 733.4 973.5 83.896 76.609 79.560 A4 0.3929 575.7 734.0 973.1 83.945 76.824 79.704 A5 0.4116 586.0 744.9 986.2 84.191 76.785 79.645 A6 0.4096 584.0 743.5 987.3 83.905 76.616 79.602

[0101] Table 5 shows that different compositions were formed according to exemplary embodiments Al to A6, as a result of which the lattice parameters changed.

[0102] FIG. 4 shows the crystal structure of the monoclinic (Sr,Ba) (Li,Ga).sub.3Ga(O,N).sub.4:Eu along the crystallographic b-axis. Ba and Sr layers are shown as hatched circles, the Ga(O,N)4 tetrahedra are widely hatched and the (Ga,Li) (O,N)4 tetrahedra are narrowly hatched. This exemplary embodiment crystallizes in the space group C2/m with the lattice parameters a=1596(1), b=647(1), c=797(1) pm and =90.00(1) and a cell volume of 0.8238(5) nm.sup.3. The tetrahedra each have common edges and/or corners, whereby two (Ga,Li) (O,N).sub.4 tetrahedra can also have a common edge with each other. The tetrahedra are each spanned by four oxygen atoms or by three oxygen atoms and one nitrogen atom or by two oxygen atoms and two nitrogen atoms or by one oxygen atom and three nitrogen atoms or by four nitrogen atoms. Li and/or Ga are arranged in the resulting tetrahedral gaps. Ba and/or Sr, which are each eightfold coordinated, are located in the respective channels formed by the tetrahedra. There are also empty channels which are free of Ba and/or Sr.

[0103] FIG. 10 shows a schematic representation of the crystal structure of a luminophore 1 that crystallizes in the tetragonal crystal structure. The circles represent Sr or Ba layers, the hatched areas represent (Li,Ga,Al)(O,N).sub.4 tetrahedra, which are corner- and edge-linked. The tetrahedra are each spanned by four oxygen atoms or by three oxygen atoms and one nitrogen atom or by two oxygen atoms and two nitrogen atoms or by one oxygen atom and three nitrogen atoms or by four nitrogen atoms. The tetrahedra form channels in which Sr or Ba atoms are arranged or which are free of Sr or Ba atoms. In this embodiment, the luminophore 1 crystallizes in space group I4/m.

[0104] Emission spectra are also recorded from exemplary embodiments A1 to A6. The respective spectra are shown in FIGS. 5A to 5F. The excitation was carried out at 460 nm in each case.

[0105] In the spectra shown in FIGS. 5 to 8, the wavelength is shown in nm against the intensity I in %.

[0106] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment Al emits yellow light with a dominant wavelength .sub.dom=561 nm when excited with blue radiation. The spectral full width at half maximum of the emission is extremely narrow with 49 nm (FIG. 5A).

[0107] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment A2 emits yellow light with a dominant wavelength .sub.dom=560 nm when excited with blue radiation. The spectral full width at half maximum of the emission is extremely narrow with 43 nm (FIG. 5B).

[0108] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment A3 emits yellow light with a dominant wavelength .sub.dom=573 nm when excited with blue radiation. The spectral full width at half maximum of the emission is extremely narrow with 44 nm (FIG. 5C).

[0109] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment A4 emits yellow-green light when excited with blue radiation (FIG. 5D). This consists of two individual emissions, the relative intensity of which can be adjusted via the precise synthesis conditions. The position of the two individual emissions of exemplary embodiment 4 is shown in detail in FIG. 7. There, the solid line represents the total emission, the dotted line the individual short-wave emission and the dashed line the individual long-wave emission. The maximum emission of the short-wave single emission is at approx. 524 nm, the maximum emission of the long-wave single emission is at approx. 567 nm. The individual full width at half maximum of the short-wave single emission is approx. 44 nm, that of the long-wave approx. 46 nm. The full width at half maximum of the entire emission band, which is created by superimposing the individual emissions, is 73 nm.

[0110] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment A5 emits yellow-green light with a dominant wavelength .sub.dom=549 nm when excited with blue radiation. The maximum of the emission is at .sub.max=538 nm (FIG. 5E). At 59 nm, the spectral full width at half maximum of the emission is with 59 nm narrower than that of known yellow-green emitting garnet luminophores, for example of the general composition (Y,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+.

[0111] The luminophore 1 or the luminophore mixture 1 according to exemplary embodiment A6 emits yellow-green light with a dominant wavelength .sub.dom=558 nm when excited with blue radiation (FIG. 5F). At 58 nm, the spectral full width at half maximum of the emission is with 58 nm narrower than that of known yellow-green emitting garnet luminophores of the general composition (Y,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+.

[0112] FIG. 6 shows all the emission spectra of the exemplary embodiments superimposed on one another. It can be seen that by varying the composition of the luminophore of the general formula Sr.sub.1-bBa.sub.bLi.sub.3Al.sub.1-xGa.sub.xO.sub.4-yN.sub.y:Eu the exact emission position can be changed and thus adapted to the respective application.

[0113] The luminophore 1 or the luminophore mixture 1 according to at least one exemplary embodiment of the present disclosure, can have clear advantages over already known luminophores due to their low spectral full width at half maximum. A commercially available garnet luminophore of the type (Y, Lu).sub.3.sup.(Al, Ga).sub.5O.sub.12: Ce.sup.3+ (hereinafter referred to as B1) is used below as an comparative example. This has a comparable color impression, measured by the dominant wavelength .sub.dom, as the luminophore 1.

[0114] Table 6 compares comparative example B1 with exemplary embodiments A1 and A4. The dominant wavelength, the full width at half maximum FWHM and the relative luminous efficacy are listed.

TABLE-US-00006 TABLE 6 luminophore .sub.dom FWHM [00001]$\frac{{}_v\left(\mathrm{exemplary}\mathrm{embodiment}\right)}{{}_v\left(\mathrm{comparative}\mathrm{example}\right)}$ B1: Y.sub.3Al.sub.3,5Ga.sub.1,5O.sub.12:Ce 561 nm 106 nm 100% A1 561 nm 49 nm 124% A4 561 nm 73 nm 117%

[0115] Both exemplary embodiments have a significantly lower spectral full width at half maximum than the comparative example. In both cases, this narrower full width at half maximum leads to a significantly higher luminous efficacy, as can be seen from the relative luminous efficacy

[00002]$\frac{{}_v\left(\mathrm{exemplary}\mathrm{embodiment}\right)}{{}_v\left(\mathrm{comparative}\mathrm{examplel}\right)}$

shown in Table 6. This approx. 24% increase in luminous efficacy can be directly advantageous for most conversion applications. When used as the sole luminophore in the conversion element of a component, this increased luminous efficacy corresponds to the efficiency gain of the conversion solution when using the luminophore 1 or the luminophore mixture 1.

[0116] Even as part of a conversion solution with other luminophores in addition to the luminophore 1 or the luminophore mixture 1, for example in white light-emitting diodes, the efficiency gain from the luminophore 1 or the luminophore mixture 1 can lead to significant improvements. However, the exact size of the efficiency gain in a mixture also depends on the other luminophores in the mixture.

[0117] In the figures, the comparison of the exemplary embodiments A1 (FIG. 8A) and A4 (FIG. 8B) with the comparative example B1 is shown again in the form of their emission spectra. The solid lines represent the emission spectra of the exemplary embodiments, the dotted lines the emission spectra of the comparative example. The significantly reduced full width at half maximum of the emission spectra of the exemplary embodiments compared to the comparative example is clearly recognizable.

[0118] FIG. 9 shows powder X-ray diffractograms calculated from the single crystal data for a monoclinic (middle diffractogram), triclinic (upper diffractogram) and a tetragonal (lower diffractogram) phase. The diffraction angle 2 is plotted in against the intensity. This shows that a luminophore mixture 1 has different phases in which the luminophore crystallizes differently and that the phases of a luminophore mixture 1 can be distinguished from each other.

[0119] The features and exemplary embodiments described in connection with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures may alternatively or additionally have further features as described in the general part.

[0120] The present disclosure is not limited to the description based on the exemplary embodiments. Rather, the present disclosure includes any new feature as well as any combination of features, which includes in particular any combination of features in the patent claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.

LIST OF REFERENCE SIGNS

[0121] 1 Luminophore [0122] 1 Luminophore mixture [0123] 10 Semiconductor chip [0124] 11 Radiation exit area [0125] 12 Active zone [0126] 20 Conversion element [0127] 30 Housing [0128] 40 Potting [0129] 100 Radiation-emitting component [0130] Wavelength [0131] I Intensity [0132] A1 Exemplary embodiment 1 [0133] A2 Exemplary embodiment 2 [0134] A3 Exemplary embodiment 3 [0135] A4 Exemplary embodiment 4 [0136] A5 Exemplary embodiment 5 [0137] A6 Exemplary embodiment 6 [0138] B1 Comparative example [0139] 2 Diffraction angle