Defect Distribution and Defect Kinetics in Undoped and Boron-Doped A-Si:H Investigated by Modulated Photocurrents

Abstract

Gap state profiles in a-Si:H around the Fermi energy have been determined by phase shift analysis of modulated photocurrents. Measurements on different samples in various light-soaked and annealed states show a general strong correlation of the defect structure with the Fermi level position, with a minimum in the DOS at E and a peak above Ef. A model of the defect structure involving a peak of D+ states above Ef is outlined that accounts for the observed correlations.