Properties of the CdTe/InSb interface studied by optical and surface analytical techniques

CdTe is an important material for radiation detectors and photovoltaic (PV) solar cells [1], with various active research activities in recent two decades [1–18]. CdTe/InSb is a significant system because of the very close lattice mismatch (∆a/a ~ 5 × 10) between them [6, 18], and therefore, the dissimilar heteroepitaxy between II–VI and III–V compounds, such as CdTe on InSb or InSb on CdTe, is very attractive for applications in optoelectronics [6, 9–11, 13, 14, 16–18]. We have recently performed a series of investigations on CdTe/InSb heterostructures grown by molecular beam epitaxy (MBE) [9, 11, 16–18]. The crystalline perfection and optical/structural properties of CdTe thin films on InSb were greatly affected by the InSb substrate growth temperature, Ts, and other growth conditions. It has been reported [5, 6, 10, 13] that In diffuses easily across the CdTe/InSb interface and modifies the optical and electronic properties of epitaxial CdTe. In this work, we present a combined study of optical and surface science analyses on the indium interdiffusion in MBE-grown CdTe/InSb heterostructures.