A new sialon Eu3.60LiSi13.78Al6.03O6.82N22.59 has been discovered via the single-particle diagnosis approach. Its crystal structure (space group P3m1) was solved and refined from single-crystal X-ray diffraction data. It has the interesting feature of two types of disorder at the Eu2 site: positional disorder (Eu2a/Eu2b) and substitutional disorder with (Si/Al)2(O/N). The structure is generalized to the formula A4-mBnC19+2mX29+m (A = Sr, La, Eu, Ce; B = Li; C = Si, Al; X = O, N; 0 ≤ m ≤ 1; 0 ≤ n ≤ 1), of which Sr3.61LiSi14.27Al5.61O6.19N23.25 (Sr-sialon, m = 0.41, n = 1) and La2.85Sr0.76LiSi14.86Al4.93O2.89N26.51 (LaSr-sialon, m = 0.40, n = 1) are two examples that have been obtained as a single-phase powder. Sr-sialon:Eu and LaSr-sialon:Eu both show blue to yellow emission, depending on the Eu concentration, whereas Sr-sialon:1% Ce shows a deep-blue emission band centered at 422 nm with a full width at half-maximum of 80 nm and an internal quantum efficiency of 80% (λex = 355 nm). The latter phosphor has very good thermal stability of both emission intensity and color. A white light-emitting diode (LED) containing the newly discovered Sr-sialon:5% Ce as the blue phosphor component shows excellent color-rendering indices (Ra = 96 and R12 = 97) with a correlated color temperature of 4255 K. This indicates that Sr-sialon:Ce is a highly promising deep-blue phosphor for illumination grade white LEDs.@en

The β-sialon:Eu2+ phosphor has superior luminescent properties as an excellent green down-conversion material for white light-emitting diodes. To take advantage of its high chromaticity and apply it to field emission displays (FEDs), the drawback of its electron insulation that impedes the electron transmission when excited by e-beam needs to be solved. In this work, a facile method was adopted to coat conductive In2O3 on the surface of β-sialon:Eu2+ phosphor, and the influence of In2O3 coating on the cathodoluminescent properties was investigated. The results show that the In2O3 coating contributes to charge elimination and significantly improves the cathodoluminescence (CL) of β-sialon:Eu2+. Under 19 kV/1.0 nA e-beam excitation, the In2O3 coated sample shows CL intensity about four times higher than that of the uncoated β-sialon:Eu2+. Moreover, no luminescence saturation occurs in coated β-sialon:Eu2+, indicating that the In2O3-coated β-sialon:Eu2+ would be a promising green emissive material for full-color FEDs.@en

Phase pure nondoped and Ce doped La₃Si_6.5Al_1.5N_9.5O_5.5 (Al containing La N-phase) samples have been obtained by solid-state reaction synthesis for the first time. 1% Ce-doped La₃Si_6.5Al_1.5N_9.5O_5.5 phosphor displays a broad excitation band ranging from UV to 410 nm, with a maximum at 355 nm. UV light excitation results in a narrow Ce³⁺ 5d-4f emission band (fwhm = 68 nm) centered at 418 nm. The emission can be tuned from 417 nm at 0.5% Ce to 450 nm at 50% Ce. A high internal quantum efficiency up to 84% is achieved for a 1% Ce doped sample, which has CIE chromaticity coordinates of x = 0.157 and y = 0.069, close to the NTSC blue standard (x = 0.155; y = 0.070). Compared to La₃Si₈O₄N₁₁:Ce phosphor, the quantum efficiency and thermal stability have been enhanced for La₃Si_6.5Al_1.5N_9.5O_5.5:Ce phosphor without shifting the emission peak wavelength. La₃Si_6.5Al_1.5N_9.5O_5.5:Ce shows less thermal quenching than La₃Si₈O₄N₁₁:Ce and no shift or change in the shape of emission spectra with increasing the temperature from 4 to 573 K. These results show that La₃Si_6.5Al_1.5N_9.5O_5.5:Ce is more efficient than any other (oxy-)nitride phosphor with an emission in the short wavelength blue region (400-450 nm). A white LED was fabricated using the La₃Si_6.5Al_1.5N_9.5O_5.5:5%Ce as a blue phosphor. The high color rendering index (Ra = 93.2, R9 = 91.4, and R12 = 89.5) obtained shows that the phosphor is a very promising conversion phosphor for white LEDs.

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La₂O₃, LaN, Si₃N₄, AlN and CeO₂ have been used as starting materials to synthesize Ce doped LaAl(Si_6−zAl_z)(N_10−zO_z) (z ≈ 1, termed the JEM phase) phosphors, via a solid-state reaction method in a gas pressure furnace at a high temperature. Nearly single phase JEM:Ce phosphors have been obtained by carefully controlling the synthesis conditions. The 5% Ce doped JEM phosphor displays a broad excitation band extending from UV to 425 nm, with a maximum at 355 nm. Excitation with 355 nm light results in a Ce³⁺ 5d–4f emission band (FWHM = 81 nm) centered at 430 nm, with a high internal quantum efficiency of 75%. The emission of the JEM:0.01Ce phosphor has only quenched 3% at room temperature as compared to the intensity at 4 K and still 57% of the luminescence is left at 573 K, which is superior to JEM:Eu phosphors. These performances make JEM:Ce phosphors very promising blue-emitting phosphors for white LED applications.@en