Bloch-Gruneisen and small polaron conduction model of electrical resistivity of ZnO nanostructures

Abstract

The temperature-dependent electrical resistivity ρ(T) of ZnO nanostructures in metallic phase is analysed by Bloch-Gruneisen [BG] model and in semiconducting phase is analyzed by small polaron conduction (SPC) model. ρ(T) shows semiconducting phase in low temperature regime, shows an absolute minimum near 180 K and increases linearly with T at high temperatures. The contributions to the resistivity by inherent acoustic phonons (ρac) as well as high frequency optical phonons (ρop) were estimated using Bloch-Gruneisen [BG] model of resistivity. Estimated contribution to resistivity by considering both phonons i.e., ωac and ωop and the zero limited resistivity are added with electron-electron interaction ωe-e to obtain the total resistivity. Resistivity in Semiconducting phase is discussed with small polaron conduction (SPC) model at low temperatures below 180 K.