Structural, electrical and optical properties of p-type transparent conducting SnO2:Al film derived from thermal diffusion of Al/SnO2/Al multilayer thin films

Highly transparent, p-type conducting SnO2:Al films derived from thermal diffusion of a sandwich structure Al/SnO2/Al multilayer thin films deposited on quartz substrate have been prepared by direct current and radio-frequency magnetron sputtering using Al and SnO2 targets. The deposited films were annealed at various temperatures for different durations. The effect of thermal diffusing temperature and time on the structural, electrical and optical performances of SnO2:Al films has been studied. X-ray diffraction results show that all p-type conducting films possessed polycrystalline SnO2 with tetragonal rutile structure. Hall-effect results indicate that 450 °C for 4 h were the optimum annealing parameters for p-type SnO2:Al films, resulting in a relatively high hole concentration of 7.2 × 1018 cm−3 and a low resistivity of 0.81 Ω cm. The transmission of the p-type SnO2:Al films was above 80%.