标题：Effect of substrate temperature on optical properties and strain distribution of ZnTe epilayer on (100) GaAs substrates
作者：Lei Zhang;Ziwu Ji;Shulai Huang;Huining Wang;Hongdi Xiao;Yujun Zheng;Xiangang Xu;Yun Lu;Qixin Guo
作者机构：School of Physics, Shandong University, Jinan 250100, China;School of Physics, Shandong University, Jinan 250100, China;School o
来源：Thin Solid Films: An International Journal on the Science and Technology of Thin and Thick Films
关键词：Zinc telluride;Gallium arsenide;Photoluminescence;Strain;Metal-organic chemical vapor deposition
摘要：The photoluminescence properties of the ZnTe epilayers grown on (100) GaAs substrates with various substrate temperatures are investigated. The spectral characteristics of both bound and free excitonic emissions measured at different measurement temperatures and excitation power, show that compared with the too low (390 ℃) or too high (440 ℃) substrate temperature, the moderate substrate temperature (around 420 ℃) is suitable to obtain a high-quality epilayer due to its narrowest spectral width and smallest strain. With increasing excitation power the peak energy of the free excitonic emission decreases linearly, while the spectral width remains an approximate constant. This implies that the decreasing peak energy should be attributed to an increasing strain with increasing the effective excited depth, and the increasing strain only reduces the bandgap, but does not cause much influence on the crystalline quality for each epilayer. Furthermore, the increasing strain also causes the ground state free excitons splitting into the light hole and heavy hole free excitons.