Control of p-type conduction in Mg doped monophase CuCrO₂ thin layers

This work aims to clarify the origin of hole conduction in undoped and Mg-doped CuCrO₂ oxide in order to have the possibility of controlling it by corresponding growth parameters. A chemical spray pyrolysis procedure for the deposition of p-type semiconductor thin films is described. The as-deposited films were amorphous. The formation of highly crystalline CuCrO₂ and Mg-doped CuCrO₂ films with a single phase delafossite structure was realized by annealing between 600 °C and 960 °C in a nitrogen atmosphere. The carrier concentration and the point defects of the samples are calculated by using the developed Kroger method of quasi-chemical reactions. p-type conductivity was predicted and observed in the undoped and Mg doped CuCrO₂ sample, and with n ∼ 10¹⁸ cm⁻³ carrier concentrations for 4%Mg doping. The electrical resistivity for a 4% Mg doped sample was 1.4 Ω·cm with a Seebeck coefficient of  +130 μ V K⁻¹ at 40 °C. By electroparamagnetic resonance spectroscopy Cr³⁺ and Cu²⁺ related defects were studied. (paper)