Low-noise metal-insulator-semiconductor UV photodiodes based on GaN

Au/SiO2/GaN metal-insulator-semiconductor photodiodes have been fabricated on Si-doped GaN epitaxial layers grown on sapphire by metalorganic vapour p hase epitaxy. The insertion of a thin SiO2 layer at the metal-semiconductor interface results in a significant decrease in the dark current density, a nd an increase in the device detectivity by more than an order of magnitude .