Photovoltaic Effect in Photoconductors

Abstract

On the basis of the assumption that the induced minority and majority carrier densities are large compared with the ``dark'' densities, a theory of the photovoltaic effect in photoconductors is presented. The theory is initially set up in general terms and then applied to specific cases: (i) abrupt homojunctions and heterojunctions between two photoconductors, (ii) abrupt homojunctions and heterojunctions between a semiconductor and a photoconductor. The existence of interfacial recombination is included in the analysis and the self‐consistency of the theory is examined. The photovoltage is evaluated in terms of the photovoltaic current and the change in Fermi energy across the interface and, in addition, an expression for the short‐circuit current is obtained. The results are used to discuss the suitability of some of the physical mechanisms which have been proposed to account for the photovoltaic phenomenon in photoconductors.