On the Electrical Conductivity of Cuprous Sulfide: A Diffusion Theory

Abstract

Mixed electrical conduction of solid cuprous sulfide at the β-phase, a p -type semiconductor, is treated theoretically, though phenomenologically, for the case where the current is maintained at a constant intensity, insufficient to electrolize out copper ions. The drift motion of acceptors (vacant copper ion lattice points) may be described with a diffusion equation, which can be linearlized when some physical assumptions are made, and then can easily be integrated under proper initial and boundary conditions. Theoretical expressions for the potential distributions are derived for the process of tending to the limiting stationary state as well as for the stationary state. Expression for the residual potential–a potential which remains after the current has been switched off and decays according as the initial homogeneity is recovered–is derived. V – I characteristics for the stationary current are also given. Calculated results are compared with experiments by Miyatani and Suzuki, exhibiting satisfactory agreements.