PUB - Publikationen an der Universität Bielefeld

Thin PIN and NIP ultraviolet detectors are numerically and experimentally studied. The influence of the front contact design on the device performance as well as the transport properties of these thin diodes are investigated. Dark current measurements of PIN and NIP devices with thin I layer (d(1) < 100 nm) indicate semi-exponential voltage dependent increase at reverse voltages, which can be explained by an electrical model applying a trap-assisted tunneling (TAT) mechanism. The same model explains the low spectral response at longer wavelengths that cannot be simulated using a standard electrical model. Comparison between Ag/PIN and Ag/NIP structure shows worse optical adjustment of Ag/NIP device mainly due to the lower optical gap of N-type a-Si:H layer. Thus, the Ag/PIN device exhibits a better performance than the Ag/NIP device. (C) 2002 Elsevier Science B.V. All rights reserved.