Origin of radiation induced damage in organic P3HT:PCBM based photocells

Abstract

Organic semiconductor photocells based upon P3HT:PCBM (1:1 by weight) have been subjected to X irradiation. The carrier lifetime has been determined using a pulsed optical method with continuous light to generate an open circuit voltage bias. No effect is observed on the carrier lifetime up to 300 krad (SiO2). However, changes in the open circuit voltage are observed and we argue that these result from compensation of the internal field which results from the built-in potential. The origin of the field modifications must lay in the presence of radiation induced trapped charge near the organic semiconductor/anode and/or cathode interfaces. © 2010 IEEE.