Ca8Mg7Si9N22:Ce3+—A Yellow-Emitting Nitride Phosphor for White Light Emitting Diodes

Nitridomagnesosilicate phosphors are promising candidates for white light emitting diodes. Here, we report a yellow nitride phosphor Ca8Mg7Si9N22:Ce3+, which exhibits a broad band emission in the spectral range of 475–675 nm under the excitation of 445 nm. The photoluminescence intensity of Ca8–xMg7Si9N22:xCe3+ (0.01 ≤ x ≤ 0.11) reaches a maximum when x = 0.05. CIE coordinates and the color purity of Ca7.95Mg7Si9N22:0.05Ce3+ are (0.449, 0.531) and 84.0%, respectively. The Ca7.95Mg7Si9N22:0.05Ce3+ phosphor exhibits a good color drifting resistance with a maximum chromaticity shift of 0.0085 at 475 K. By combining the as-synthesized yellow nitride phosphor Ca7.95Mg7Si9N22:0.05Ce3+ and red nitride phosphor SrLiAl3N4:Eu2+ with a commercial blue InGaN chip, an all-nitride white light emitting diode device is fabricated, and a warm white light is generated with chromatic coordinates (0.471, 0.364) and color temperature of 2194 K.