Effect of Cu concentration on the structural and optoelectronic properties of ZnO:Cu:Al prepared by the sol-gel deposition method

This study investigate the effects of Cu concentration on ZnO:Cu:Al films by the sol-gel deposition method. It was found that the ZnO:Cu:Al films consist of wrinkled micro-fibers, which become more prominent as the Cu concentration increases. Furthermore, the introduction of Cu suppresses crystallite growth and creates structural defects in the ZnO films. An increase in the Cu concentration also reduces the optical transmittance of the deposited films due to structural disorder. Electrical measurements suggest that a stable p-type ZnO can be obtained by tuning the Cu to Al ratio.