Low temperature growth of MgGa2O4 films for deep ultraviolet photodetectors

MgGa2O4 films were grown on the (0001) sapphire substrates by using pulsed laser deposition at substrate temperatures ranging from 100 to 500 °C. The influences of substrate temperature on the structural and optical properties of the films have been systematically investigated. Deep ultraviolet (DUV) photodetectors were demonstrated by using the MgGa2O4 films as wavelength-selective absorber layers. The photodetectors based on the MgGa2O4 films grown at 500 °C exhibited excellent peak responsivity (0.18 A/W) around 220 nm, high rejection ratio (R220 nm/R350 nm = 104), and reproducibility. Our results obtained in this work indicate the pulsed laser deposition is a promising technique for obtaining high quality MgGa2O4 film at low growth temperature, paving the way to realize high performance DUV photodetectors based on MgGa2O4 film for novel optoelectronic applications.