Selective UV Detection by AlGaN/GaN-Based MSM Photo Detector for Integration with Silicon

The present research reports the fabrication and performance evaluation of an AlGaN/GaN-based metal-semiconductor-metal (MSM) ultraviolet (UV) photo detector on silicon (111) substrate. The MSM device has been fabricated with aluminium (Al) in an inter-digitized (IDE) geometry on the molecular beam epitaxially grown epilayer. Substantially high photo current as 9.5 mA has been resulted under the illumination of 365 nm wavelength UV as compared to the dark current of 409μA with photo-to-dark current ratio of 23.22 and very high responsivity of 15798 A/W. Rise time as 1.01 seconds and fall time as 5.17 seconds has been observed after transient analysis of the devices. High carrier concentrations at the heterojunction due to polarization has been attributed for relatively larger photo current as compared to previous literature.