Determination of the Lifetime in As Doped a-Se from Transient Photocurrents using Laplace Transform Technique

Abstract

The identification, in our earlier papers, of the discrete energy levels in stabilized a-Se indicate that doping with As in the limit of 0.2-0.5% suppresses the shallow defect and increases the density of the deep one. It may be added at this point that an undesirable decrease in the hole lifetime τ was found to accompany the introduction of As in the a-Se lattice, which was attributed to a new hole trap. More analysis is clearly needed to resolve these questions. For these reasons we have developed a technique to calculate the lifetime. The obtained results confirm the image of the density of states near the valance band.