Pulsed laser deposition of ZnGa2O4 thin films on Al2O3 and Si substrates for deep optoelectronic devices applications

Due to the ultra-wideband gap, high transmittance in the ultraviolet (UV) region, and excellent environmental stability, zinc gallium oxide (ZnGa2O4) has attracted considerable interest in deep-ultraviolet photodetectors. Here, ZnGa2O4 thin film was fabricated on different substrates by pulsed laser deposition with a post-annealing process under an oxygen atmosphere. It is found that the substrates have a great impact on the morphology, structure, and crystal quality of thin film. After annealing, the thin film quality has been improved. The metal-semiconductor-metal photodetector shows excellent reproducible characteristics and fast response performance, which demonstrates great potential in next-generation optoelectronic devices.