Abstract
An in-situ Kelvin probe has been used to measure accurately and conveniently built-in potential profiles of junctions made by depositing undoped and/or doped a-Si: H layers on a conducting substrate. The method is specifically described for a Schottky barrier. The density of states in the vicinity of the interface is obtained from the data and the density of surface states is determined to be approximately 1·7 × 1011 cm−2.