Author:
Zhou Wen-Guang,Jiang Dong-Wei,Shang Xiang-Jun,Wu Dong-Hai,Chang Fa-Ran,Jiang Jun-Kai,Li Nong,Lin Fang-Qi,Chen Wei-Qiang,Hao Hong-Yue,Liu Xue-Lu,Tan Ping-Heng,Wang Guo-Wei,Xu Ying-Qiang,Niu Zhi-Chuan
Abstract
We compared the photoluminescence (PL) properties of AlInAsSb digital alloy samples with different periods grown on GaSb (001) substrates by molecular beam epitaxy. Temperature-dependent S-shape behavior is observed and explained using a thermally activated redistribution model within a Gaussian distribution of localized states. There are two different mechanisms for the origin of the PL intensity quenching for the AlInAsSb digital alloy. The high-temperature activation energy E
1 is positively correlated with the interface thickness, whereas the low-temperature activation energy E
2 is negatively correlated with the interface thickness. A quantitative high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) study shows that the interface quality improves as the interface thickness increases. Our results confirm that E
1 comes from carrier trapping at a state in the InSb interface layer, while E
2 originates from the exciton binding energy due to the roughness of the AlAs interface layer.
Subject
General Physics and Astronomy