Facile deposition and characterization of large area highly conducting and transparent Sb-doped SnO_2 thin film

摘要

We have deposited a large area (10x10 cm(2)) Sb-doped SnO2 (ATO) thin film transparent conducting electrode (TCE) using chemical spray pyrolysis method. The XRD analysis confirms tetragonal crystal structure of ATO thin film with significant preferred orientation. The XPS analysis clearly indicates the presence of Sb in +5 charge state when substituted into the SnO2 lattice. The UV-Vis transmittance spectra of the film showed average transmittance of 77.5% at 550 nm and the calculated direct band gap value was 3.82 eV. As-deposited ATO film exhibited lowest sheet resistivity and resistance of 6.715x10(-4) Omega cm and 31.91 Omega/square respectively due to Sbdopant effect into the Sn lattice. Doping with Sb into SnO2 exhibits high carrier concentration of 7.899x10(20) cm(-3) and mobility of 28.45 cm(2)/Vs resulting in enhanced electrical transport properties. The variation of the sheet resistance of the large area deposited film is estimated across every 1x1 cm(2) surface area. Variation of sheet resistance of the ATO film as a function of annealing temperature and duration was found to be appreciably stable. Kelvin probe study yielded a surface work function of 5.14 eV for the ATO film indicating the suitability to serve as an indium-free alternate TCE for optoelectronic device applications.