荧光粉是制备白光发光二极管(LED)关键材料之一,其性能直接影响着白光LED亮度、色度、色温及显色指数.但是,现有荧光粉由于稳定性差、光衰严重等问题,使白光LED不能达到预期目标,迫切需要改进其制备工艺.采用高温固相合成法制备YAG:Ce3+黄色荧光粉,研究温度、Ce添加量等对荧光粉粒度、荧光强度等理化性质影响规律,并评价该荧光粉与蓝光LED芯片组合形成白光LED的性能.结果表明,烧结温度高于1400℃时,荧光粉呈立方结构纯YAG晶相;温度越高,形成的粉末粒径越大,发光强度越高;Ce掺杂量x=0.06时,烧结的荧光粉发光强度最大;封装形成的Φ3 mm白光LED亮度为5581 cd/m2,色坐标x=0.2626,y=0.2753,色温Tc=13000 K.
Highly conductive and transparent Al-doped ZnO (AZO) thin films were prepared from a zinc target containing Al (1.5 wt.%) by direct current (DC) and radio frequency (RF) reactive magnetron sputtering. The structural, optical, and electrical properties of AZO films as-deposited and submitted to annealing treatment (at 300 and 400°C, respectively) were characterized using various techniques. The experimental results show that the properties of AZO thin films can be further improved by annealing treatment. The crystallinity of ZnO films improves after annealing treatment. The transmittances of the AZO thin films prepared by DC and RF reactive magnetron sputtering are up to 80% and 85% in the visible region, re- spectively. The electrical resistivity of AZO thin films prepared by DC reactive magnetron sputtering can be as low as 8.06 × 10?4 ??cm after annealing treatment. It was also found that AZO thin films prepared by RF reactive magnetron sput- tering have better structural and optical properties than that prepared by DC reactive magnetron sputtering.
LI LiFANG LiangCHEN XimingLIU GaobinLIU JunYANG FengfanFU GuangzongKONG Chunyang
