Nanocrystalline SnO2 and Au:SnO2 thin films prepared by direct current magnetron reactive sputtering

Abstract

Nanocrystalline pure and gold doped SnO2(Au:SnO2) films were prepared on unheated glass substrates by dc magnetron reactive sputtering and, subsequently, the as deposited films were annealed in air. The films structure, surface morphology, photoluminescence, electrical and optical properties were investigated. After annealing the as deposited SnO2 films, crystallinity increased and the surface roughness decreased. The intensity of PL peaks increases sharply with the annealing temperature. The optical transmittance of the films was around 89% after annealing the as deposited SnO2 films at 450 °C. The as deposited Au:SnO2 films show better crystallinity than the as deposited SnO2 films, the average grain size was around 4.4 nm. The emission peaks of Au:SnO2 films are slightly blue shifted as compare to undoped SnO2 films. The Au:SnO2 films show the lowest electrical resistivity of 0.001 Ωcm with optical transmittance of 76%, after annealing at 450 °C.