Synthesis and characterization of In doped ZnO thin film as efficient transparent conducting oxide candidate

In this work, we have successfully prepared the highly conducting and transparent In doped ZnO thin films on glass substrate using sol-gel spin-coating technique. Indium was incorporated with different concentrations of 1, 2, and 4 at.%. The effect of indium doping on the structural, optical and electrical properties of the produced films have been investigated. X-ray diffraction analysis showed that all the films were polycrystalline with a hexagonal würtzite structure.The growth along (002) orientation was only preferred for 2 at.% doping concentration. The transparency of In doped ZnO thin films varied from 70 to 92% in visible range. Zinc oxide thin film doped with 4 at.% concentration revealed the largest grain size, the lowest optical gap, the highest intrinsic defects amount, and the lowest resistivity which was found to be 6.10 × 10−4 Ω cm. These In doped ZnO thin films can have big interest in solar cell industry.