温度对Al0.5Ga0.5As/AlAs分布布喇格反射器的反射谱影响

采用光学传输矩阵理论对Al0.5Ga0.5As/AlAs材料分布布喇格反射器(DBR)进行理论研究,分析了－10℃到100℃的范围内,温度变化对不同DBR结构的反射光谱影响.结果表明：随着温度的升高,传统20周期DBR的反射光谱向长波长方向移动,速率约0.05 nm/℃,其中由线热膨胀系数带来的影响小于0.001 nm/℃.当传统DBR的周期数增大时,温度对DBR光谱反射率的影响在减小,同时DBR的反射谱峰值波长发生红移.为了降低温度对DBR反射光谱的影响,提出一种新型的复式DBR结构.分析指出：该复式DBR比传统DBR有更大的反射光谱半峰宽,基本能覆盖同温度的AlGaInP LED电致发光光谱,这对提高LED的出光效率有现实意义.

Effect on Reflectance Spectra of Al0.5Ga0.5As/AlAs Distributed Bragg Reflector by Temperature

The reflectance spectra of Al0.5Ga0.5As/AlAs distributed Bragg reflector（DBR）at different temperature are calculated by optical transfer matrix theory.The differences of the reflectance spectra of different DBR structures at －10℃~100℃ are analyzed.The results show that with the temperatures raising,the reflectance spectra of conventional 20-period DBR has about 0.05 nm/℃ red-shift,including the ~0.001 nm/℃ red-shift by the thermo-expand coefficient calculated.When the periods of conventional DBR are increased,the changes of the DBR′s reflectivity at different temperature effect are reduced,simultaneity the peak-wavelength of the DBR′s reflectance spectra is shifted to longer wavelengths and become steady when the period of DBR is over 20.In order to reduce the changes from temperature and improve the DBR reflective performance,a novel mulriple-type DBR is put forward.The peak width at half max (FWHM) of the reflectance spectra of the novel DBR is wider than that of conventional DBR,which is important to enhance light extraction from LED.