Photoconductivity detected S‐W related defect levels in a‐Si:H

A constant photocurrent method was used to study the Staebler‐Wronski effect on a‐Si:H samples with a coplanar configuration of electrodes on Schottky diodes. Results on the coplanar samples are partly influenced by surface (interface) band bending but both samples show a higher value of optical absorption coefficient α in an absorption shoulder after prolonged illumination. Some experimental details of the method are discussed. A model for the density of states in p‐type a‐Si