A novel yellow-emitting SrAlSi4N7:Ce3+ phosphor for solid state lighting: Synthesis, electronic structure and photoluminescence properties

作者：Ruan, Jian; Xie, Rong-Jun^*; Funahashi, Shiro; Tanaka, Yoshinori; Takeda, Takashi; Suehiro, Takayuki; Hirosaki, Naoto; Li, Yuan-Qiang

来源：Journal of Solid State Chemistry, 2013, 208: 50-57.

DOI：10.1016/j.jssc.2013.09.040

• Photoluminescence
• Electronic structure
• Phosphors
• Nitride
• White LEDs

Ce3+-doped and Ce3+/Li+-codoped SrAlSi4N2 phosphors were synthesized by gas pressure sintering of powder mixtures of Sr3N2, AlN, alpha-Si3N4, CeN and Li3N. The phase purity, electronic crystal structure, photoluminescence properties of SrAlSi4N2:Ce-3 (Ce3+/Li+) were investigated in this work. The band structure calculated by the DMol(3) code shows that SrAlSi4N7 has a, direct band gap of 3.87 eV. The single crystal analysis of Ce3+-doped SrAlSi4N2 indicates a disordered Si/Al distribution and nitrogen vacnacy defects. SrAlSi4N2 was identified as a major phase of the fired powders, and Sr5Al5Si21N35O2 and AlN as minor phases. Both Ce3+ and Ce3+/Li+ doped SrAlSi4N2 phosphors can be efficiently excited by near-UV or blue light and show a broadband yellow emission peaking around 565 nm. A highest external quantum efficiency of 38.3% under the 450 nm excitation was observed for the Ce3+/Li+-doped SrAlSi4N2 (5 mol%). A white light LED lamp with color temperature of 6300-K and color rendering index of Ra=78 was achieved by combining Sr0.92Al1.03Si3.997N\94\maccounttest14=t0005_18193(7):Ce-0.03(3+) with a commercial blue InGaN chip. It indicates that SrAlSi4N2:Ce3+ is a promising yellow emitting down-conversion phosphor for white LEDs.

• 出版日期2013-12