LAUSR

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.