Carrier transport in In-doped CuO thin films

Temperature-dependent conductivity and thermopower measurements are carried out for undoped and In-doped CuO thin films. We investigate the effects of In-doping on carrier transport properties of CuO thin films in the temperature range of 300?T?<?400?K. Carrier transport is dominated by simple thermally activated conduction in the undoped film. On the other hand, small polarons play an essential role in the carrier transport properties in the In-doped films. By increasing the In content, the conduction behaviour transits from adiabatic limit to the non-adiabatic limit, and the conductivity decreases.