Tuning Electrical and Optical Properties of SnO2 Films: Influence of Sb Dopant Concentration and Coating Layer in Spin-Coating Process

This study investigates the optical and electrical properties of antimony (Sb)-doped tin oxide (SnO2), commonly referred to as ATO, transparent conducting thin films synthesized via a wet chemical route. The films were fabricated using a sol-gel method combined with spin-coating. The effects of Sb doping concentrations (1, 3, and 5 mol%) and the number of coating layers (5 and 10) on the films' properties were systematically examined. ATO films were deposited onto glass substrates at a constant spin speed of 2000 rpm, followed by calcination at 600 °C for 2 hours. X-ray diffraction (XRD) analysis confirmed the formation of a tetragonal SnO2 structure with no secondary phases. Optical measurements revealed high transparency in the visible range, with transmittance values between 60% and 80%. The lowest resistivity of 0.16 Ω·m was achieved with 5 mol% Sb and 10 coating layers, which also corresponded to the highest carrier concentration of 2 × 10^9 cm^-3, as determined by Hall effect measurements. These results demonstrate that optimized ATO films possess desirable properties for electronic and optoelectronic device applications.