A New Model for Interpreting the Electric Conduction Phenomena in Cu2O Single Crystals

A new model, consisting in a continuous distribution of acceptor states, is proposed in order to interpret the conduction phenomena observed in Cu2O at low and moderate temperatures. It explains the exponential thermal variation of the conductivity, its exponential dependence on the activation energy (Meyer-Neldel's empiric rule), and the large range of conductivities (10−13 to 10−3 Ω−1cm−1). It allows an interpretation of the existence and shape of the continuous extrinsic background absorption. Its use in the analysis of the experimental results reveals an exponential relationship between mobility and activation energy. On this basis, the thermal variation of the apparent mobility is explained in a simple way.