Impact of Ta doping on the optoelectronic and catalytic properties of SnO2 thin films

Spray-deposited un-doped SnO2 and SnO2:Ta (Ta: 0.5, 1.0, 1.5, and 2.0 wt.%) thin films were studied through various characterization techniques. The XRD results confirmed the tetragonal phase of SnO2, and the calculated crystallite size varied between 33 and 43 nm. The SEM micrographs showed that Ta-dopant significantly altered the morphology of SnO2 thin films. The chemical states of SnO2:Ta were confirmed by XPS analysis. A high average transmittance (similar to 80%) was obtained, and band gap values varied between 3.60 and 3.42 eV. Relatively, minimum electrical resistivity (9.7 x 10(-4) Omega.cm), Hall mobility (43 cm(2)/V.s), low value of sheet resistance (32 Omega/square), and high optoelectronic efficiency (phi = 1.29 x 10(-3) Omega(-1)) were obtained for 1.0 wt.% Ta-doping. The highest photodegradation efficiency (94.38%) was achieved against malachite green aqueous dye solution for 1.5 wt.% Ta-doping. These results clearly show that 1.0 and 1.5 wt.% SnO2:Ta films could be potential candidates for photocatalytic dye degradation and TCO applications. [GRAPHICS] .