Graphene-silicon-on-insulator (GSOI) Schottky diode photodetectors.

Graphene-silicon (GS) Schottky junctions have been demonstrated as an efficient architecture for photodetection. However, the response speed of such devices for free space light detection has so far been limited to 10s-100s of kHz for wavelength λ >500 nm. Here, we demonstrate GS Schottky junction photodetectors fabricated on a silicon-on-insulator substrate (SOI) with response speeds approaching 1 GHz, attributed to the reduction of the photo-active silicon layer thickness to 10 μm and with it a suppression of speed-limiting diffusion currents.

Towards substrate engineering of graphene-silicon Schottky diode photodetectors.

Graphene-silicon Schottky diode photodetectors possess beneficial properties such as high responsivities and detectivities, broad spectral wavelength operation and high operating speeds. Various routes and architectures have been employed in the past to fabricate devices. Devices are commonly based on the removal of the silicon-oxide layer on the surface of silicon by wet-etching before deposition of graphene on top of silicon to form the graphene-silicon Schottky junction.