Study on the doping effect of Sn-doped ZnO thin films

Tin doped zinc oxide (ZnO:Sn) thin films were deposited onto Pyrex glass substrates by chemical spray pyrolysis technique starting from zinc acetate (CH3CO2)2Zn⋅2H2O and tin chloride SnCl2. The effect of Sn doping on structural, optical and electrical properties was investigated. The atomic percentages of dopant in ZnO-based solution were y = [Sn4+]/[Zn2+] = 0%, 0.2%, 0.6% and 1%. It was found that all the thin films have a preferential c-axis orientation. With increase of Sn doping, the peak position of the (0 0 2) plane was shifted to the high 2θ values. ZnO:Sn demonstrated obviously improved surface roughness, reduced average crystallite size, enhanced Hall mobility and reduced resistivity. Among all of the tin doped zinc oxide in this study, films doped with 0.6 at.% Sn concentration exhibited the best properties, namely a Hall mobility of 9.22 cm2 V−1 s−1, an RMS roughness of 37.15 nm and a resistivity of 8.32 × 10−2 Ω cm.

Figure optionsDownload as PowerPoint slideHighlights
► The n-type ZnO:Sn thin films with low resistivity were obtained by spray method.
► All the thin films of ZnO:Sn had a preferential c-axis orientation.
► The electrical properties of ZnO:Sn are extremely sensitive to the tin doping.
► Film doped with 0.6 at.% Sn concentration exhibited the best properties.