Chemical and electronic structure of InSb-CdTe interfaces

Abstract

The microscopic interactions at heterojunctions formed between cleaned surfaces of InSb and CdTe have been investigated by low-energy electron diffraction and soft x-ray photoelectron spectroscopy. Layers of CdTe have been deposited on 1×1 (110) cleaved InSb and on c(2×8) (100) sputter cleaned and annealed surfaces, for various substrate temperatures. The valence-band offset has been measured and compared with theoretical predictions for layers deposited on room-temperature substrates. For layers deposited onto substrates at elevated temperatures typical of those employed in molecular beam epitaxial growth, the interface is complex and consists of a region rich in indium and tellurium, presumed to be indium telluride. The thickness of this layer is temperature dependent and may be several tens of angstroms.