Employment of III-nitride/silicon heterostructures for dual-band UV/IR photodiodes

Employment of layered structures made of semiconductor materials with different optical absorption bands is a new way of realizing either broad band spectrum or selective multiple band photodetectors. A new concept of structures fabricated using stacked semiconducting layers to obtain a multi band spectral response is reported. Based on this approach, fabrication of a Solar-blind dual-band UV/IR photodetectors is demonstrated. Optimization of the device was carried out by modeling of the electric field distribution and developing tunneling barriers. The optimized Solar-blind UV/IR photodiode UV spectral response turns-on approximately around 265 nm (solar-blind) and peaks at 230 nm with a responsivity of approximately 0.0018 A/W. The IR diode response peaks at 1000nm with a responsivity of approximately 0.01 A/W.