Seminars Archive

Spectromicroscopy as a Tool for Probing Lateral Inhomogeneities in Semiconductor Interfaces

Abstract
III-VI layered semiconductors represent a good playground for the study of lateral inhomogeneities in semiconductor interfaces. It is well known that defects and/or contaminants affect the band lineup in the formation of an interface. The layered structure of these materials and their stability in UHV makes the realization of very clean and very flat surfaces relatively easy. This allows performing a clean study, virtually free from structural problems and unwonted complications. Some examples of spectromicroscopy studies will be presented for both SB and heterojunctions, where we have stressed the lateral resolution of the SPEM technique to analyze variations in band bending. These variations will be proven to be of local origin. A comparison with non-laterally-resolved PES will be done for the Si/GaSe system showing how the averaging over a large area smear out this effect. For the case of Al/GaS where Al strongly reacts with the substrate we will show how variations in the band bending can be imaged directly.