Stationary Primary Photocurrents for the Characterization of a-Si:H Pin-Diodes

Abstract

Carrier transport in amorphous silicon pin-diodes has been analyzed by charge collection in transient and in steady state mode. Whereas transient experiments yield µτ-products governed by deep trapping life time, from steady state collection of electrons excited by different photon energies locally resolved µτ -products in pin-structures have been evaluated reflecting recombination life time. A considerable decrease of µτ in undoped bulk material in the neighborhood of the p/i-interface has to be attributed to the shift of FERMI-level towards the valence band, which means an intrinsic effect, not necessarily related to a higher defect density at the interface.