Substrate Temperature Dependent Physical Properties of Spray Deposited Antimony-Doped SnO2 Thin Films

Abstract

Antimony doped tin oxide (ATO) thin film has been widely explored as an alternative transparent conducting oxide (TCO) electrode. The ATO thin films are not yet commercialized due to issues in reproducibility and stability of its transparent conducting properties. In this work, properties of spray deposited ATO thin films are explored as a function of substrate temperature. The deposited ATO thin films are investigated using ultraviolet-visible spectrometer, Hall Effect, and temperature-dependent four probe methods. The film deposited at 450°C was found to possess relatively higher transmittance of 89 % with a wide bandgap of 3.81 eV. Furthermore, it also showed good electrical properties such as high carrier concentration (3.12 × 1020 cm−3), high mobility (25.1 cm2/Vs), low sheet resistance (24.9 Ω/□), and an excellent figure of merit value (1.25 × 10−2 Ω−1). The obtained results are correlated with substrate temperature. The activation energies of the ATO thin films are estimated using Arrhenius plot from the temperature-dependent electrical measurement to elucidate the conduction mechanism. The ATO films were also annealed at various temperature to study the stability of the sheet resistance. The results obtained imply the optimized ATO thin films to be a potential alternative TCO candidate.