Si/Graphene exotic type IMPATT (p+-n-n+-) Opto-sensor: First experimental observation

On-chip DC characterization study has been performed on exotic-type Si/Graphene Avalanche Transit Time (ATT) device for ultra-fast optical-sensing. The performance of the newly proposed device has further been compared with conventional narrow and wide band gap semiconductor based p⁺-n-n⁺ devices. It has been observed that at X-band frequencies, the new class of device outperforms Si/SiC/GaN and their heterostructure counterparts, in terms of better RF power density (∼$1W$ and $8.1W$), RF conversion efficiency (6 % and 18 %) and much better quantum efficiency (93 % and 91.5 %), respectively for device active-region-widths of 15 μm and 25 μm. Standard Chemical Vapor Deposition (CVD) route has been followed to fabricate the new class of device. Further, the authors have studied the applicability of the newly developed devices for optical-sensing. This comprehensive study reveals that the Device Under Test (DUT) exhibits photo responsivity at least 10 times better than its counter parts. Thus, the study will be useful for future applications in single-photon-detection for defence and civil sectors.