Field Dependence of 1 and 2 Photon Charge Generation in Anthracene and Phenazine

Abstract

Charge carrier generation through photexcitation with strongly absorbed light and very weakly absorbed light has been compared for anthracene and phenazine crystals. No attempt was made to prepare clean surfaces, but purified crystals were used. The field dependence for strongly absorbed light was similar for both crystals, superlinear at low fields, linear at high fields. For weakly absorbed light, the photo generation of charge in anthracene could be described as Onsager type behavior, generation in phenazine could not. These results are discussed in terms of the charge generation process.