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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 was grown by Czochralski method. The optical and thermal stability of the white LED were characterized by absorption spectrum, excitation emission spectrum and temperature change spectrum. Its photoelectric properties. Ce: YAG wafers can be effectively excited by blue light at a wavelength of 466 nm, resulting in a broad emission band in the 500-700 nm range. The transitions of 4f → 5d orbital of Ce3 + correspond to five absorption peaks at 202, 219, 247.3, 347.4 and 455.5 nm, respectively, and quantify the 5d level energy of splitting, followed by 21954, 29154, 4037, 45662 and 49505 cm-1 . Ce3 + 2F7 / 2 energy increase resulted in a decrease of luminescence intensity (13.28%), which was not as large as that of the national standard of Ce: YAG single crystal white LED light source The packaging process, from the chip, the drive current, the thickness of the chip and additives are discussed in four aspects. The results show that Ce: YAG single crystal is a new white LED fluorescent material.