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

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.