Effect of (Al, Zn, Cu, and Sr) doping on structural, optical and electrical properties of sprayed SnO2 thin films

Abstract

Tin dioxide thin films deposited onto a glass substrate were prepared by spray pyrolysis technique, and then doped with different elements which are: Al, Zn, Cu, and Sr by electroplating method, these elements were chosen for their different atomic radii. XRD illustrate that all the films were polycrystalline with a tetragonal rutile structure and a strong preferred orientation of (200) plane. Uv-vis spectrophotometer specters showed that the highest average transmittance of Al/SnO₂ film was about 86.77% in the visible region and the Sr/SnO₂ film had the highest band gap of 3.95 eV. From the MEB images, the morphological characteristics improved when the SnO₂ thin films doped with Al and Zn but the opposite happened when it doped with Cu and Sr. The four-point probe showed that the best sample was for Al/SnO₂ because it had the highest electrical conductivity around 692.306 (Ω.cm) ^-1.