Effect of Ta doping on the characteristic features of spray-coated SnO2

Abstract

In present work, undoped and Ta-doped SnO2 thin films were fabricated via a simple and cheap spray pyrolysis technique. The Ta-doping level was varied from 0at.% to 5at.% in the step of 1at.%. Large pyramidal and small densely-packed tetragonal SnO2 particles were observed by X-ray diffraction and scanning electron microscope. Atomic force microscope analysis indicated that root mean square roughness values of films changed from 26.7nm to 51.6nm with Ta-doping. The electrical and optical measurements revealed that the films had a degenerate n-type semiconductor property. The resistivity, sheet resistance, carrier concentration, mobility, and optical band gap values of films varied between 1.11×10−2Ωcm–2.35×10−3Ωcm, 130.66Ω/□–26.97Ω/□, 2.72×1019cm−3–1.12×1020cm−3, 20.68cm2V−1s−1–30.78cm2V−1s−1, and 3.43eV–3.94eV, respectively. As a result of this study, it is concluded that characteristic properties of SnO2 can be greatly improved with Ta-doping.