Solar-blind AlGaN-based Schottky photodiodes with low noise and high detectivity Available to Purchase

We report on the design, fabrication, and characterization of solar-blind Schottky photodiodes with low noise and high detectivity. The devices were fabricated on $n−/n+$ AlGaN/GaN heterostructures using a microwave compatible fabrication process. True solar-blind operation with a cutoff wavelength of $∼274 nm$ was achieved with $AlxGa1−xN$ $(x=0.38)$ absorption layer. The solar-blind detectors exhibited $<1.8 nA/cm2$ dark current density in the 0–25 V reverse bias regime, and a maximum quantum efficiency of 42% around 267 nm. The photovoltaic detectivity of the devices were in excess of $2.6×1012 cm Hz1/2/W,$ and the detector noise was $1/f$ limited with a noise power density less than $3×10−29 A2/Hz$ at 10 kHz.