Examples were suggested which illustrated the marked macroscopic effects which occurred in semiconductor systems as a result of nanoscale interface phenomena. In some cases, there was an interplay of several competing defect-driven mechanisms. For single-crystalline ZnO, the role of near-surface defects in the formation of Au Schottky contacts was studied. High concentrations of shallow donors in the surface and sub-surface regions led to barrier thinning; resulting in increased tunneling. Alternatively, the presence of deep defects near to the contact interface promoted tunneling by defect-assisted hopping. Nanoscale electronic and chemical studies showed that the independent reduction of shallow donors or deep defects significantly improved the rectifying performance of Au/ZnO contacts. It was found that the processing of ZnO using remote O and H plasmas permitted the controlled tailoring of the chemical and physical surface properties.

Role of Defects at Nanoscale ZnO and Cu(In,Ga)Se2 Semiconductor Interfaces. Y.M.Strzhemechny: Journal of Vacuum Science and Technology A, 2006, 24[4], 1233-7