Structural, optical and electrical properties of ZnO films grown on c-plane sapphire and (1 0 0)γ-LiAlO2 by pulse laser deposition

ZnO thin films were grown on single-crystal γ-LiAlO2 (LAO) and sapphire (0 0 0 1) substrate by pulsed laser deposition (PLD). The structural, optical and electrical properties of ZnO films were investigated. The results show that LAO is more suitable for fabricating ZnO films than sapphire substrate and the highest-quality ZnO film was attained on LAO at the substrate temperature of 550 °C. However, when the substrate temperature rises to 700 °C, lithium would diffuse from the substrate (LAO) into ZnO film which makes ZnO film on LAO becomes polycrystalline without preferred orientation, the stress in ZnO film increases dominantly and the resistivity of the film decreases exponentially.