Properties of Al-doped ZnO films grown by atmospheric pressure MOCVD on different orientation sapphire substrates

ABSTRACTAl-doped ZnO films were grown on different orientation sapphire substrates (sapphire-R, C, M, A) at 400–600 °C via the atmospheric pressure aerosol-assisted MOCVD technique. The influence of deposition temperature and orientation of sapphire substrate on the microstructure, electrical and optical properties of ZnO-Al films was investigated. Epitaxial films grown on sapphire-R substrates exhibited the best electrical properties: carrier mobility was 50–60 cm2 V−1 s−1, resistivity <10−3 Ω cm. The conditions of post-deposition treatment of films (gas atmosphere during film cooling after deposition, ex-situ annealing) had a marked influence on the electrical properties of films.