Band alignment at the CdTe/InSb (001) heterointerface

Contributors:   Xingye Wang, Calli Campbell, Yong-Hang Zhang, and Robert J. Nemanich

ABSTRACT

CdTe/InSb heterojunctions have attracted considerable attention because of its almost perfect lattice match and the presence of nonoctal interface bonding. This heterojunction is a model heterovalent system to describe band offsets. In this research, molecular beam epitaxy was used to deposit a ∼5 nm epitaxial CdTe (001) layer on an InSb (001) surface. Monochromatic x-ray photoemission spectroscopy and ultraviolet photoemission spectroscopy were used to characterize the electronic states of clean InSb and CdTe surfaces and CdTe/InSb (001) heterostructures. A room temperature remote hydrogen-plasma process was used to clean the surfaces prior to characterization. The results indicate a valence band offset of 0.89 eV and a type-I (straddling gap) alignment for the CdTe/InSb (001) heterostructure interface. In addition, In-Te bonding was observed at the interface. Downward band bending of the InSb is attributed to excess electrons introduced by nonoctal In-Te interface bonding.

Publisher: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films,   Volume: 36, Issue 3,   031101 ||  Published: 2018-05 ||   PDF (1.13 MB) ||   Read More...