PHOSPHORS AND PHOSPHOR-CONVERTED LEDS

Abstract

The present invention relates to alkaline earth aluminate phosphors, to a process for the preparation thereof and to the use thereof as conversion phosphors. The present invention also relates to an emission-converting material comprising at least the conversion phosphor according to the invention, and to the use thereof in light sources, in particular pc-LEDs (phosphor converted light emitting devices). The present invention furthermore relates to light sources, in particular pc-LEDs, and to lighting units which comprise a primary light source and the emission-converting material according to the invention.

Claims

1. Compound of formula (1),
(AE).sub.a-d-v-yA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eM.sup.3.sub.vE.sub.c-e-yX.sub.x+yN.sub.e+v.DFormula(1) where the following applies to the symbols and indices used: AE is selected from the group consisting of Ca, Sr, Ba or mixtures of these elements; D is selected from the group consisting of Eu, Mn, Yb, Sm, Ce or mixtures of these elements; A is selected from the group consisting of Na, K or mixtures of these elements; M.sup.1 is selected from the group consisting of B, Al, Ga, In, Tl, Sc or mixtures of these elements; M.sup.2 is selected from the group consisting of C, Si, Ge, Sn or mixtures of these elements; M.sup.3 is selected from the group consisting of Y, Lu, La or mixtures of these elements; E is selected from the group consisting of O, S, Se, Te or mixtures of these elements; X is selected from the group consisting of F, Cl, Br, I or mixtures of these elements; N is a trivalent nitride ion; 0.65a1; 0y0.1a where a is as defined above; 0v0.1a where a is as defined above; 10.667b11.133; 17.00c17.35; 0x5; 0e5; 0.0584a/b0.0938; 0.0375a/c0.0588; 2a+3b=2c+x; with the proviso that x0 or y0 or v0 or e0 when AE=Ba and M.sup.1=Al.

2. Compound according to claim 1 wherein AE is selected from the group consisting of Ba or a mixture of Ba and Sr or a mixture of Ba and Ca, which comprises a maximum of 10 atom-% of Sr or Ca, respectively, with respect to the total content of AE.

3. Compound according to claim 1 wherein D is selected from Eu or a mixture of Eu and Mn, which comprises a maximum of 10 atom-% of Mn with respect to the total amount of AE+Eu+Mn.

4. Compound according to claim 1 wherein A is K and the index y is in the range 0y0.05a where a has the meaning given in claim 1.

5. Compound according to claim 1 wherein M.sup.1 is selected from the group consisting of Al or mixtures of Al with Ga or Al with In and wherein the total amount of Ga or In, respectively, is 10 atom-% of the total amount of M.sup.1.

6. Compound according to claim 1, wherein the compound is selected from the compounds of the formulae (2) to (11),
(Ba.sub.1-zSr.sub.z).sub.a-d-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eF.sub.c-e-yX.sub.x+yN.sub.eFormula (2)
(Ba.sub.1-zSr.sub.z).sub.a-d-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eF.sub.c-e-yX.sub.x+yN.sub.eFormula (3)
(Ba.sub.1-zCa.sub.z).sub.a-d-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eF.sub.c-e-yX.sub.x+yN.sub.eFormula (4)
(Ba.sub.1-zCa.sub.z).sub.a-d-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eF.sub.c-e-yX.sub.x+yN.sub.eFormula (5)
Ba.sub.a-d-v-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eM.sup.3.sub.vE.sub.c-e-yX.sub.x+yN.sub.e+vFormula (6)
Ba.sub.a-d-v-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eM.sup.3.sub.vE.sub.c-e-yX.sub.x+yN.sub.e+vFormula (7)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wB.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vF.sub.c-e-yX.sub.x+yN.sub.e+vFormula (8)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wGa.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vF.sub.c-e-yX.sub.x+yN.sub.e+vFormula (9))
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wIn.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vF.sub.c-e-yX.sub.x+yN.sub.e+vFormula (10)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wSc.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vF.sub.c-e-yX.sub.x+yN.sub.e+vFormula (11) where the symbols and indices have the meanings given in claim 1 and 0d1, 0z0.1; and 0w0.1.

7. Compound according to claim 1 wherein E is selected from the group consisting of 0, S or mixtures of the elements.

8. Compound according to claim 1 wherein X is selected from the group consisting of F, Cl or mixtures thereof, preferably F and wherein 0.001x+y0.1.

9. Compound according to claim 1 wherein 0.70a0.80.

10. Compound according to claim 1, selected from the compounds of the formulae (2a) to (11a)
(Ba.sub.1-zSr.sub.z).sub.a-d-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eO.sub.c-e-yF.sub.x+yN.sub.eFormula (2a)
(Ba.sub.1-zSr.sub.z).sub.a-d-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eO.sub.c-e-yF.sub.x+yN.sub.eFormula (3a)
(Ba.sub.1-zCa.sub.z).sub.a-d-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eO.sub.c-e-yF.sub.x+yN.sub.eFormula (4a)
(Ba.sub.1-zCa.sub.z).sub.a-d-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eO.sub.c-e-yF.sub.x+yN.sub.eFormula (5a)
Ba.sub.a-d-v-yEu.sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (6a)
Ba.sub.a-d-v-y(Eu,Mn).sub.dA.sub.yM.sup.1.sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (7a)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wB.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (8a)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wGa.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (9a)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wIn.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (10a)
(AE).sub.a-d-v-yD.sub.dA.sub.y(Al.sub.1-wSc.sub.w).sub.b-eM.sup.2.sub.eM.sup.3.sub.vO.sub.c-e-yF.sub.x+yN.sub.e+vFormula (11a) where the symbols and indices have the following meanings: AE is selected from the group consisting of Ba or mixtures of Ba with Ca or Ba with Sr where the maximum amount of Ca or Sr, respectively, is 10 atom-% with respect to the total amount of AE+D; D is selected from the group consisting of Eu or a mixture of Eu and Mn; A is selected from K or a mixture of K and Na where the maximum amount of Na with respect to the total amount of K and Na is 10 atom-%; is selected from the group consisting of B, Al, Ga, In, Sc or mixtures of two of these elements, preferably Al, Ga, In or mixtures of two these elements; M.sup.2 is selected from the group consisting of Si, Ge or mixtures of these elements; M.sup.3 is selected from the group consisting of Y, Lu and La; O is a divalent oxygen anion; 0.70a0.80; 0z0.05; 0.03d0.25; 10.93b11.067; 17.2c17.3; with the proviso that x0 or y0 or e0 when z=0 and M.sup.1=Al in formulae (2a) to (5a); and furthermore with the proviso that x0 or y0 or v0 or e0 when M.sup.1=Al in formulae (6a) and (7a); and furthermore with the proviso that x0 or y0 or v0 or e0 when AE=Ba and w=0 in formulae (8a) to (11a).

11. Compound according to claim 1 wherein the compound is coated.

12. Process for the preparation of a compound according to claim 1, comprising the steps: a) preparation of a mixture comprising AE, D, M.sup.1, E, optionally X and/or optionally A and/or optionally M.sup.2 and/or M.sup.3 and/or optionally N; and b) calcination of the mixture at elevated temperature.

13. A conversion phosphor for the partial or complete conversion of the near-UV or violet emission of a light source into light having a longer wavelength, which comprises a compound according to claim 1.

14. Light source which comprises at least one primary light source and at least one compound according to claim 1.

15. Light source according to claim 14 wherein the primary light source is a near-UV or violet LED diode and the light source comprises at least one compound emitting in the blue region of the spectrum, at least one compound emitting in the green region of the spectrum and at least one compound emitting in the orange or red region of the spectrum.

16. A conversion phosphor comprising a phosphor emitting light of a longer wavelength than its excitation source wavelength, said phosphor being a compound according to claim 1.

17. The phosphor according to claim 16, wherein the excitation source wavelength is near-UV or violet.

Description

EXAMPLES

[0133] The phase formation of the samples was in each case checked by means of X-ray diffractometry. For this purpose, a Rigaku Miniflex II X-ray diffrac-tometer with Bragg-Brentano geometry was used. The radiation source used was an X-ray tube with Cu-K radiation (=0.15418 nm). The tube was operated at a current strength of 15 mA and a voltage of 30 kV. The measurement was carried out in an angle range of 1080 at 10.Math.min.sup.1.

[0134] Reflection spectra were determined using an Edinburgh Instruments Ltd. fluorescence spectrometer. For this purpose, the samples were placed and measured in a BaSO.sub.4-coated integrating sphere. Reflection spectra were recorded in a range from 250-800 nm. The white standard used was BaSO.sub.4 (Alfa Aesar 99.998%). A 450 W Xe lamp was used as excitation source.

[0135] The excitation spectra and emission spectra were recorded using an Edinburgh Instruments Ltd. fluorescence spectrometer fitted with mirror optics for powder samples. The excitation source used was a 450 W Xe lamp.

Synthesis of Inventive Compounds

Example 1: Synthesis of Ba.SUB.0.63.Eu.SUB.0.12.Al.SUB.11.O.SUB.17.25..F.SUB.0.0015

[0136] 2.486 g BaCO.sub.3

[0137] 0.422 g Eu.sub.2O.sub.3

[0138] 11.21 g Al.sub.2O.sub.3

[0139] 0.131 g BaF.sub.2

[0140] The starting materials are mixed in a mechanical mortar for 10 minutes and fired at 1550 C. for 5 h in an H.sub.2:N.sub.2 (5:95) atmosphere with an intermediate dwell step at 1350 C. for 3h in 100% N.sub.2 atmosphere. After firing, the material is ground into a fine powder, washed in water, dried and sieved using a 50 m nylon sieve to narrow the particle size range.

Example 2: Synthesis of Ba.SUB.0.63.Eu.SUB.0.12.Al.SUB.10.8.Sc.SUB.0.2.O.SUB.17.25..F.SUB.0.0015

[0141] This synthesis is performed as described in example 1 using the following starting materials:

[0142] 2.486 g BaCO.sub.3

[0143] 0.422 g Eu.sub.2O.sub.3

[0144] 11.012 g Al.sub.2O.sub.3

[0145] 0.276 g Sc.sub.2O.sub.3

[0146] 0.131 g BaF.sub.2

Example 3: Synthesis of Ba.SUB.0.63.Eu.SUB.0.12.Al.SUB.10.5.Sc.SUB.0.5.O.SUB.17.25..F.SUB.0.0015

[0147] This synthesis is performed as described in example 1 using the following starting materials:

[0148] 2.486 g BaCO.sub.3

[0149] 0.422 g Eu.sub.2O.sub.3

[0150] 10.706 g Al.sub.2O.sub.3

[0151] 0.690 g Sc.sub.2O.sub.3

[0152] 0.131 g BaF.sub.2

Example 4: Synthesis of Ba.SUB.0.63.Eu.SUB.0.12.Al.SUB.10.8.Si.SUB.0.15.O.SUB.17.025.N.SUB.0.15..F.SUB.0.0015

[0153] This synthesis is performed as described in example 1 using the following starting materials:

[0154] 2.486 g BaCO.sub.3

[0155] 0.422 g Eu.sub.2O.sub.3

[0156] 10.859 g Al.sub.2O.sub.3

[0157] 0.180 g SiO.sub.2

[0158] 0.123 g AlN

[0159] 0.131 g BaF.sub.2

[0160] The synthesis processes given above are just the typical synthesis examples. It is possible by the same synthesis procedure to produce other inventive compounds. It is also possible to use different gases and temperatures in the manufacturing process of the materials.

[0161] The materials in the following Table 1 are produced in analogy to the compounds described in examples 1 to 4 using stoichiometric amounts of the corresponding starting materials and firing at temperatures between 1450 and 1550 C. It is possible for the samples prepared at 1450 C. that higher quantum efficiencies are obtained when a higher synthesis temperature is used. Unless otherwise stated, the starting materials were fired at 1550 C. following the procedure of Example 1. Table 1 furthermore shows the spectroscopic results (emission wavelengths as well as quantum efficiencies) of the samples.

TABLE-US-00001 TABLE 1 Compounds synthesized with spectroscopic data (emission wavelength and quantum efficiency) Emission Peak iQE Ex. Composition [nm] [%] 5 Ba.sub.0.69Sr.sub.0.0225Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 515 86 6 Ba.sub.0.69Ca.sub.0.0225Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 511 88 7 Ba.sub.0.7125Eu.sub.0.0375Al.sub.10.7753Ga.sub.0.225O.sub.17.25F.sub.0.0015 518 89 8 Ba.sub.0.7125Eu.sub.0.0375Al.sub.10.6253In.sub.0.375O.sub.17.25F.sub.0.0015 516 84 9 Ba.sub.0.735Eu.sub.0.015Al.sub.11O.sub.17.25F.sub.0.0015 507 78 10 Ba.sub.0.675Eu.sub.0.075Al.sub.11O.sub.17.25F.sub.0.0015 518 87 11 Ba.sub.0.705Eu.sub.0.0375Al.sub.11O.sub.17.25F.sub.0.0015 518 88 12 Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25F.sub.0.0015 519 95 13 Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Si.sub.0.15O.sub.17.025N.sub.0.15F.sub.0.0015 521 87 14 Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 517 90 15 Ba.sub.0.6525Eu.sub.0.075La.sub.0.0225Al.sub.11O.sub.17.2613F.sub.0.0015 515 84 16 Ba.sub.0.6525Eu.sub.0.075La.sub.0.0225Al.sub.11O.sub.17.2605F.sub.0.0015 516 83 17 Ba.sub.0.69Eu.sub.0.06Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 90 18 Ba.sub.0.66Eu.sub.0.09Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 516 84 19 Ba.sub.0.63Eu.sub.0.12Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 518 70 20 Ba.sub.0.6Eu.sub.0.15Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 518 64 21 Ba.sub.0.57Eu.sub.0.18Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 58 22 Ba.sub.0.54Eu.sub.0.21Al.sub.10.9Sc.sub.0.1O.sub.17.25F.sub.0.0015 515 56 23 Ba.sub.0.69Eu.sub.0.06Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 52 24 Ba.sub.0.66Eu.sub.0.09Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 55 25 Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 519 62 (prepared at 1450 C.) 26 Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 519 90 (prepared at 1550 C.) 27 Ba.sub.0.6Eu.sub.0.15Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 518 60 28 Ba.sub.0.57Eu.sub.0.18Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 56 29 Ba.sub.0.54Eu.sub.0.21Al.sub.10.8Sc.sub.0.2O.sub.17.25F.sub.0.0015 515 55 30 Ba.sub.0.63Eu.sub.0.12Al.sub.10.5Sc.sub.0.5O.sub.17.25F.sub.0.0015 516 82 31 Ba.sub.0.57375Eu.sub.0.12K.sub.0.028125Al.sub.11O.sub.17.25F.sub.0.0015 516 93

[0162] The compositions of the starting materials used in Examples 7, 8, 15 and 31 which involve at least one of the elements Ga, In, La and K are as follows:

Example 7: Synthesis of Ba.SUB.0.7125.Eu.SUB.0.0375.Al.SUB.10.7753.Ga.SUB.0.225.O.SUB.17.25..F.SUB.0.0015

[0163] This synthesis is performed as described in example 1 using the following starting materials:

[0164] 3.750 g BaCO.sub.3

[0165] 0.175 g Eu.sub.2O.sub.3

[0166] 14.165 g Al.sub.2O.sub.3

[0167] 0.565 g Ga.sub.2O.sub.3

[0168] 0.055 g AlF.sub.3x3H.sub.2O

Example 8: Synthesis of Ba.SUB.0.7125.Eu.SUB.0.0375.Al.SUB.10.6253.In.SUB.0.375.O.SUB.17.25..F.SUB.0.0015

[0169] This synthesis is performed as described in example 1 using the following starting materials:

[0170] 3.750 g BaCO.sub.3

[0171] 0.175 g Eu.sub.2O.sub.3

[0172] 14.480 g Al.sub.2O.sub.3

[0173] 1.390 g In.sub.2O.sub.3

[0174] 0.055 g AlF.sub.3x3H.sub.2O

Example 15: Synthesis of Ba.SUB.0.6525.Eu.SUB.0.075.La.SUB.0.0225.Al.SUB.11.O.SUB.17.2613..F.SUB.0.0015

[0175] This synthesis is performed as described in example 1 using the following starting materials:

[0176] 3.435 g BaCO.sub.3

[0177] 0.350 g Eu.sub.2O.sub.3

[0178] 14.990 g Al.sub.2O.sub.3

[0179] 0.100 g La.sub.2O.sub.3

[0180] 0.140 g BaF.sub.2

Example 31: Synthesis of Ba.SUB.0.57375.Eu.SUB.0.12.K.SUB.0.028125.Al.SUB.11.O.SUB.17.25..F.SUB.0.0015

[0181] This synthesis is performed as described in example 1 using the following starting materials:

[0182] 3.020 g BaCO.sub.3

[0183] 0.565 g Eu.sub.2O.sub.3

[0184] 14.990 g Al.sub.2O.sub.3

[0185] 0.075 g K.sub.2CO.sub.3x0.5H.sub.2O

[0186] 0.175 g BaF.sub.2

[0187] The fluorine content of the phosphors shown in Table 1 was determined independently with two different analytical techniques, wherein the first technique is semi-quantitative Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and the second technique is quantitative X-Ray Photoelectron Spectroscopy (XPS). Both techniques are well known to a person skilled in the art. TOF-SIMS is a technique used to analyze the composition of solid surfaces and thin films by sputtering the surface of a sample with a focused primary ion beam and collecting and analyzing ejected secondary ions. The mass/charge ratios of these secondary ions are measured with a mass spectrometer to determine the elemental, isotopic, or molecular composition of the surface to a depth of 1 to 2 nm. Due to the large variation in ionization probabilities among different materials, SIMS is generally considered to be a qualitative technique, although quantitation is possible with the use of standards. XPS is a surface-sensitive quantitative spectroscopic technique that measures the elemental composition at the parts per thousand range, empirical formula, chemical state and electronic state of the elements that exist within a material. XPS spectra are obtained by irradiating a material with a beam of X-rays while simultaneously measuring the kinetic energy and number of electrons that escape from the top 0 to 10 nm of the material being analyzed.

[0188] TOF-SIMS:

[0189] The surface of the samples was exposed to a pulsed ion beam which ejects secondary ions from the surface. The mass and chemical element of the ejected secondary ions was determined from their specific time of flight (TOF).

[0190] Instrument: IONTOF, TOF-SIMS-300

[0191] Analysis ion: Bi.sub.x.sup.+, 25 keV

[0192] Sputter ion: Cs.sup.+, 1 keV

[0193] Depth profiles were also measured. The erosion of the surface was carried out by sputtering with cesium ions of energy 1 keV.

[0194] XPS:

[0195] The surface of the samples was irradiated with monochromatic X-rays having a defined energy so that photoelectrons were released from all atoms being located in a near-surface region. The kinetic energy of the photoelectrons was measured by a hemispherical energy analyzer. By converting such kinetic energies into binding energies, the corresponding chemical elements can be determined from which the photoelectrons were released.

[0196] All XPS measurements were carried out with a PHI Quantera SXM instrument using the following parameters:

[0197] Excitation: monochromatic Al-K radiation (1486.6 eV/15 kV)

[0198] Recording angle: 45

[0199] Pass energy: 280 eV (overview)/55+140 eV (detail) [0200] 140 eV (depth profile)

[0201] Chamber pressure: ca. 3.Math.10.sup.6 Pa

[0202] Measurement area: 200 m

[0203] Sputter ion: Ar

[0204] Erosion rate: 1 keV (ca. 10 nm/min)

[0205] Sputter area: 1 mm1 mm

[0206] All samples were first pressed onto an indium carrier film, then mounted on the sample holder and introduced into the ultra-high-vacuum chamber of the XPS device. At first, overview spectra were recorded from the powder's surface to determine the elements which are present. Then, energetically higher-resolved spectra were recorded from the detected elements. In addition, depth profiles of the elements were recorded.

[0207] A fluorine content of F.sub.0.0015 as indicated for the Examples in Table 1 was determined using the above-mentioned TOF-SIMS and XPS methods.

[0208] Table 1 shows that variation of the composition has a relatively strong influence on the position of the emission peak. Furthermore, the efficiency changes with changing composition. This is analogous for the Eu.sup.2+ concentration series, presented in the table for two materials with different Sc.sup.3+ co-doping in place of Al.sup.3+. The shift of the peak position with increasing divalent europium content in the host lattice first follows an expected track (red-shift), while at higher doping levels there is unexpected blue-shift. Furthermore, there is a difference in emission efficiency depending on the synthesis temperature, as can be seen from examples 25 and 26.

[0209] The -alumina structure of all compounds was confirmed by X-ray diffraction. Examples of the XRD results are shown in FIG. 1 to 3.

[0210] The emission spectra of some selected compounds are shown in FIGS. 4 and 5. The excitation spectra of some selected compounds are shown in FIG. 6. The excitation spectra remain essentially the same with respect to their spectral position, although the relative intensity varies for different compositions. The emission spectra show that varying the composition of the material influences the peak maximum position.

Example 32: Spectroscopic Comparison of a Sample According to the Prior Art with the Inventive Material

[0211] A comparative sample according to the prior art (Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25), which does not contain any fluorine, was prepared as described in the literature (A. L. N. Stevels, J. of Luminescence 17 (1978), 121-133). This sample shows blue and green luminescence with a major contribution of the blue part, while the inventive material (Ba.sub.0.63Eu.sub.10.12Al.sub.11O.sub.17.25.F.sub.0.0015 according to example 1), containing fluorine, under the same conditions shows mostly green emission with only a minor contribution of the blue light. The results show that the fluorine incorporation enhances the green emission even under, unfavorable, UV excitation. The emission spectra are shown in FIG. 7.

[0212] Furthermore, the fluorine inclusion into the host lattice is supported by the fact that the theoretical limit to the green luminescence in the discussed material of about QE=40% (based on literature data A. L. N. Stevels, J. of Luminescence 17 (1978), 121-133) is confirmed in the present case for the sample according to the prior art (QE40-50%). In contrast, the inventive material shows a much improved efficiency with QE typically above 80% and in some compositional variants with a QE95%, in all the cases under a 410 nm violet excitation.

[0213] LED Examples

[0214] General Instructions for Manufacturing and Measurement of Phosphor-Converted-LEDs (Pc-LEDs)

[0215] A mass of m.sub.p,n (where the index n denotes the number of the phosphor component of the phosphor blend related to the particular LED-example) of the phosphor component mentioned in the particular LED-example is weighed together with the other phosphor components (masses of m.sub.p,n, n>1) and subsequently mixed (e.g. by use of a planetary centrifugal mixer). To the phosphor blend obtained by the process mentioned before, a mass of m.sub.Silicone of an optical transparent silicone is added and subsequently homogenously mixed by means of a planetary centrifugal mixer, in order to obtain a phosphor concentration of c.sub.p (in % by mass) in the whole mass of the silicone-phosphor slurry. The slurry is then dispensed onto a blue or near-UV or UV- or violet-light-emitting LED-die by means of an automated dispensing equipment and cured under elevated temperatures, depending on the properties of the used transparent silicone. The LED-dies used in the examples mentioned below emit visible violet light at a wavelength of 407 nm or 411 nm, respectively, and are driven at an operating current of 350 mA. The lighting-technology-related parameters are obtained by means of a spectrometer from Instrument Systems, type CAS 140 CT combined with an integration sphere ISP 250. The characterization of the pc-LED is performed by measurement of the wavelength-dependent spectral power density. The spectrum of the emitted light from the pc-LED is then used for the calculation of colour coordinates x and y (CIE 19312-degree observer), photometric fluxes .sub.v, Correlated Colour Temperature (CCT) and the Color Rendering Index (CRI).

Example 33: LEDs Using Phosphor According to the Invention

[0216] The inventive LEDs are manufactured as described above. The phosphors used in the following examples are summarised in Table 2. The results obtained from the pc-LED examples are summarised in Table 3.

TABLE-US-00002 TABLE 2 Phosphors used in the pc-LED examples Phosphor component no. Phosphor material 1 (blue) (Ba, Sr, Ca).sub.3MgSi.sub.2O.sub.8: Eu.sup.2+ 2 (green), acc. to the present invention Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25F.sub.0.0015 3 (red) CASN: Eu.sup.2+

TABLE-US-00003 TABLE 3 Results of pc-LED examples Parameter LED example a LED example b Peak-wavelength 407 410 of LED dye m.sub.p,1/g 0.53 0.53 m.sub.p,2/g 5.86 5.86 m.sub.p,3/g 0.11 0.11 M.sub.silicone/g 3.5 3.5 c.sub.p/wt. % 65 65 CIE x 0.418 0.419 CIE y 0.399 0.397 CCT/K 3296 3277 CRI 91 91 photometric 43 43 flux/Im

[0217] As can be easily seen, both LEDs give the same results with respect to colour, etc. These results are therefore independent of the exact emission colour of the LED chip.

DESCRIPTION OF THE FIGURES

[0218] FIG. 1: XRD pattern of Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25.F.sub.0.0015 (example 1) showing the phase pure -alumina structure.

[0219] FIG. 2: XRD pattern of Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Sc.sub.0.2O.sub.17.25.F.sub.0.0015 (example 2) showing the phase pure -alumina structure.

[0220] FIG. 3: XRD pattern of Ba.sub.0.63Eu.sub.0.12Al.sub.10.8Si.sub.0.15O.sub.17.025N.sub.0.15.F.sub.0.0015 (example 4) showing the phase pure -alumina structure.

[0221] FIG. 4: Emission spectrum of Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25.F.sub.0.0015 (example 1) under excitation at 410 nm.

[0222] FIG. 5: Emission spectra of Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu, Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu,SC, Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu, Si, N (solid, dashed and dotted lines, respectively) under excitation at 410 nm.

[0223] FIG. 6: Excitation spectra of Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu, Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu,SC, Ba.sub.0.75Al.sub.11O.sub.17.25.F.sub.0.0015:Eu, Si, N (solid, dashed and dotted lines, respectively) for emission at 521 nm.

[0224] FIG. 7: Comparison of emission spectra of a sample according to the prior art (Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25) with the inventive material (Ba.sub.0.63Eu.sub.0.12Al.sub.11O.sub.17.25.F.sub.0.0015) under UV excitation at 270 nm.

[0225] FIG. 8: Spectrum of the LED of example 33a.

[0226] FIG. 9: Spectrum of the LED of example 33b.