Effect of substrate temperature on reactive RF magnetron sputtered SnO2 thin films for photovoltaic applications

SnO2 thin films were deposited using reactive RF magnetron sputtering technique at different substrate temperatures such as RT (S1), 200 °C (S2) and 400 °C (S3) in order to obtain highly crystalline as well as highly transparent films. The effect of substrate temperature on the structural, optical and electrical properties of SnO2 thin films was also studied. The observed XRD patterns indicated the formation of SnO2 in tetragonal phase with primitive lattice structure. UV–Vis-NIR spectroscopic analysis exhibited the high optical transparency (>90%) at the wavelength of 600 nm. Hall Effect measurements demonstrated the n-type conductivity of SnO2 thin films with high carrier concentration (-2.40 × 1020 to −8.40 × 1018 cm−3) and mobility (1.62 to 10.83 cm2/Vs) as well as low resistivity in the order of 10-2 Ω.cm for S1-S3. However, S2 (200 °C) is considered as potential candidate for photovoltaic applications because of reasonably high carrier concentration, enhanced crystalline nature, and also low processing temperature in addition to the suitable optical band gap (3.7 eV).