采用提拉法生长了白光LED用Ce：YAG单晶，通过吸收光谱、激发发射光谱和变温光谱对其光学性能和热稳定性进行了表征，并研究了晶片用于封装白光LED光源中各因素对其光电性能的影响。Ce：YAG晶片能被466 nm波长的蓝光有效激发，产生500~700 nm范围内的宽发射带。Ce3+的4f→5d轨道的跃迁吸收对应于202、219、247.3、347.4和455.5 nm五个吸收峰，据此量化分裂的5d能级能量，依次为21954、29154、40437、45662和49505 cm-1。温度升高， Ce3+的2F7/2能量升高导致了发光强度的降低，可降低幅度(13.28%)不大，比肩国家标准且要优于目前商用白光光源的Ce：YAG单晶制白光LED光源的封装工艺，从芯片、驱动电流、晶片厚度和添加物四方面进行讨论。研究结果表明， Ce：YAG单晶是一种新型白光LED用荧光材料。
The Ce:YAG single crystal for white light-emitting diode (WLED) application was grown by the Czochralski method. The thermal stability and optical properties of samples were characterized by absorption spectrum, photolumi-nescence spectra and temperature-dependent PL spectra. The photoelectric performance of WLEDs fabricated by the Ce:YAG single crystal were also measured. It is found that the Ce:YAG single crystal shows a broad emission band from 500 nm to 700 nm under blue light (wave length 466 nm). Absorption peaks, located at 202, 219, 247.3, 347.4 and 455.5 nm, are due to 4f→5d transition, and the energy of 5d orbits is divided into 21954, 29154, 40437, 45662 and 49505 cm-1. As the temperature increases, the PL intensity is reduced because of a higher energy of the 2F7/2, and the damping upon PL intensity by the Ce:YAG single crystal (13.28%) are much lower than that by commercially available phosphors (30%). When the current is at a standard state and the luminous flux of emission blue light is around 3.7 lm, the most suitable thickness for the Ce:YAG single crystal is 0.5 mm. Since the WLED fabricated by the Ce:YAG single crystal prepared in present work meets all requirements in related GB codes, and its performance is better in comparison with that of the commercially available one, the Ce:YAG single crystal will possibly be used to fabricate new-type WLED devices.
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