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 0 at.% to 5 at.% in the step of 1 at.%. 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 26.7nmto 51.6 nm 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 x 10(-2) Omega cm-2.35 x 10(-3) Omega cm, 130.66 Omega/square -26.97 Omega/square, 2.72 x 10(19) cm(-3)-1.12 x 10(20) cm(-3), 20.68 cm(2) V-1 s(-1)-30.78 cm(2) V-1 s(-1), and 3.43 eV-3.94 eV, respectively. As a result of this study, it is concluded that characteristic properties of SnO2 can be greatly improved with Ta-doping. (C) 2015 Elsevier B.V. All rights reserved.