AlGaN-based structures on sapphire for visible blind Schottky-barrier UV photodetectors: toward high-performance device applications

摘要

Abstract: Al$-x$/Ga$-1$MIN@x$/N material system, whose bandgaplies in the 3.42-6.2 eV range, is extremely interestingfor visible and solar blind UV photodetectorapplications. This paper describes the deviceperformances of Al$-x$/Ga$-1$MIN@x$/N UV Schottkybarrier photodetectors for visible-blind applicationsgrown on c-oriented sapphire, with a detailed balancewith the basic materials properties. Conventional lowtemperature grown AlN or GaN were used in allapplications. High quality Schottky barrier photodiodesmade of Epitaxial Lateral Overgrown (ELOG) GaN are alsopresented. All Schottky barrier devices show a fasttime response, a high UV-visible rejection factor, andhigh absolute values of above bandgap responsivities. Anew application of AlGaN UV Schottky barrierphotodetectors to monitor the biological action of thesolar UV radiation, as well as the device performanceof high quality GaN and AlGaN Metal Semiconductor Metalwith cutoff wavelengths as short as 310 nm, aredescribed in detail. !54