Investigation of the gap state distribution in a-Si:H using post-transit pulse analysis

Abstract The gap state distribution in a-Si:H has been investigated using the recently developed Post-Transit Photocurrent Analysis (PTPA). Our analysis, restricted to data obtained from samples with blocking contacts or samples in the p-i-n configuration, provides convincing evidence that PTPA genuinely probes the gap state distribution. Upon light-soaking we find a direct relationship between the gap state density and the mobility-lifetime product. A maximum in the density of states at approximately 0.6 eV shifts towards mid-gap upon light-soaking. The temperature dependence of the peak yields information about the value of the attempt-to-escape frequency.