Negligible Photoconductivity Efficiency and Impurity Sensitive Absorption Fine Structure at the Low Energy Tail of π-π* Transition in Trans-Polyacetylene

Abstract

Photocurrent spectra normalized by incident light intensity together with high-resolution optical absorption spectra have been obtained in the visible and near IR regions using carefully prepared very pure samples. The photocurrent efficiency is practically zero at the low energy tail of the π-π^* absorption band and gradually increases with the photon energy, becoming very high on the high energy side. Oxygen doping produces a photocurrent peak at 1.4 eV and a corresponding series of sharp absorption bands which stick to the intrinsic absorption band edge.