Sol–gel derived (Li, Mg): ZnO films with high c-axis orientation and electrical resistivity

ZnO films with high orientation and resistivity have a great potential in piezoelectrical devices. In this work, Li- and Mg-doped ZnO films on glass substrates were prepared by sol–gel spin-coating and two-step growth. The effects of the dopants and heating temperature on c-axis orientation and resistivity of the resulting films were investigated. For the ZnO films formed by two-step growth, the orientation of the first grown layer played a significant role in c-axis orientation of the film. The results showed that Mg doping into Li:ZnO films could improve c-axis orientation and increase the resistivity, the optimized (Li,Mg):ZnO film had a highly c-axis orientation, small grain size and resistivity of 11.18×107 Ω·cm.