Band Gap Engineering of Amorphous MgSnO Film for Deep-Ultraviolet Photodetection

Deep-ultraviolet (DUV) detectors have great application prospects in many fields. In this letter, after Sn was doped in MgO by magnetron sputtering, a band gap regulation of the MgSnO from 4.13 eV to 4.67 eV was conducted with a good absorption coefficient for deep-ultraviolet light realized. On this MgSnO film obtained, interdigital electrodes were constructed via mask evaporation technique, based on which a photoconductive deep-ultraviolet detector with metal-semiconductor-metal structure was fabricated. This detector has exhibited excellent characteristics, including low dark current (10−9 A), relatively-high switching ratios (102), ultra-high responsivity (5.87 A/W) and a superior external quantum efficiency (3937%) under 10 V bias.