高亮度LED中ODR反光镜反射率温度特性研究

对Al/SiO2、Al/ITO、Au/SiO2、Au/ITO构成的ODR(Omni-directional reflector)结构,对应400～800 nm的不同波长,在不同温度下,对于反光镜的反射率的影响,进行了研究。提出了在460 nm的蓝光波段,Al/SiO2合金温度在500～700 K时,反射率会达到最小值,温度在700 K以上时,又到常温值,且略微增加;Al/ITO反射率是随着温度变化单调下降的,因此要在Al反光镜的表面采用Ti/Al/Ti/Au的结构,改善反光镜的特性;620 nm的红光波段,Au/SiO2和Au/ITO的合金温度在700 K时,具有最理想的反射率,且Au/SiO2结构的反射效果要优于Au/ITO结构。用实验的方式进行了验证,分析了可能造成反射率变化的原因。

Temperature Characteristic of Reflectivity of Omni-directional Reflector in the High Brightness Light-emitting Diodes

This paper researches the influence of different anneal temperature to the reflectivity of the Al/SiO_2,Al/ITO,Au/SiO_2 Au/ITO ODR corresponding to the wavelength of 400nm～800 nm.It is proposed that,in the wavelength of 460 nm,the reflectivity is down to minimum when the anneal temperature of Al/SiO_2 reflector is 500～700 K,and when temperature above 700°C,it is back to normal and increase a little;the one of Al/ITO decreases monotonic with the increasing temperature,and Ti/A/Ti/Au structure is applied to improve the characteristic of the reflector.Moreover,it is also noted that,in the wavelength of 620nm,reflectivity of Au/SiO_2 and Au/ITO both achieve the maximum with the anneal temperature of 700K,and the performance of Au/SiO_2 ODR is superior to that of Au/ITO.We validates the conclusion with the experiment and analysis the cause of the variation of the reflectivity.