Influence of Surface Structures on Quality of CdTe(100) Thin Films Grown on GaAs(100) Substrates**Supported by the National Key Research and Development Program of China under Grant Nos 2017YFB0405704 and 2017YFA0305400, the 1000-Young Talent Program of China, and the Shanghai Sailing Program under Grant No 17YF1429200.

Abstract

We report the epitaxial growth of single-crystalline CdTe(100) thin films on GaAs(100) substrates using molecular beam epitaxy. By controlling the substrate pre-heated temperature with adjustable Te flux, three different reconstructed surfaces are realized, and their influence on the subsequent CdTe growth is investigated. More importantly, we find that both the presence of a thin native oxide layer and the formation of Ga-As-Te bonds at the interface enable the growth along the (100) orientation and help to reduce the threading dislocations and other defects. Our results provide new opportunities for compound semiconductor heterogeneous growth via interfacial engineering.