The effect of intrinsic defects on the hole transport in Cu2O

Abstract

Structural and electrical properties of Cu2O bulk samples are characterized by X-Ray diffraction (XRD) and Hall effect measurements. The variation of the carrier concentration with temperature is explained in terms of the thermal activation energy of an acceptor level originating from intrinsic defects. An acceptor energy level of 0.22 eV above the edge of the valance band has been obtained. A high compensation ratio has been estimated as 0.49 by using an expression valid for a compensated material. The strong compensation of donors in Cu2O samples is predicted due to a high density of native acceptor defects. The temperature dependence of the mobility is interpreted in terms of Seto's model which was proposed for polycrystalline materials. Utilizing Seto's model, various electrical parameters of the present samples such as grain boundary potential, surface densities of trap states, the average size of the crystallites and Debye screening length have been determined.