Low temperature thermopower and electrical conductivity in highly conductive CuInO2 thin films

Abstract

This is the first report on the detailed study on low temperature (6–300 K) electrical conductivity and Seebeck coefficient on copper indium oxide polycrystalline thin films deposited on soda lime glass substrates by a reactive evaporation method. These films, characterized using various experimental techniques, show the highest electrical conductivity (20 to 125 S cm⁻¹) reported to date as well as n- and p- type conductivity. The electrical conductivity mechanisms, based on Mott's, Seto's and Arrhenius models, in different temperature regimes, comprise of variable range hopping, grain boundary effect and activated thermal conduction. Most interestingly, the thin films manifest a high thermoelectric power factor and absorption in the UV region, indicating their potential in thermoelectric and UV energy conversion device fabrication, respectively.