Self-powered vacuum ultraviolet photodetector based on a BAlN/Si/BAlN double heterojunction.

Hexagonal boron nitride (hBN) and Al-doped BxAl1-xN films were grown on Si(100) substrates by means of a radio frequency magnetron sputtering technique. These films have been fabricated into hBN/Si and BAlN/Si heterojunctions, respectively. The heterojunction of hBN/Si exhibited an excellent response to vacuum ultraviolet (VUV) light at 185 nm. By incorporating Al into hBN, the BAlN/Si heterostructure demonstrated a response performance and weak self-powered characteristics. In order to further improve the self-powering performance, a BAlN/Si/BAlN double-heterojunction has been designed and then prepared, leading to high-sensitivity detection with a light-to-dark current ratio of 3600 and a responsivity of 70 mA/W at 185 nm under zero bias.