Toward A Metal-Free Contact Based On Multilayer Epitaxial Graphene On 4H-SiC

We report on a promising approach to realize bifacial silicon carbide (SiC) based ultraviolet (UV) photodetectors with no metallic electrodes. The ohmic contact regions, consisting of a few conductive carbon-rich layers, while maintaining the necessary UV sensitivity for the photodetector’s operation, are directly realized using a nanosecond-pulsed excimer laser. By combining structural, optical, and electrical characterization, we demonstrate how this treatment allows the formation of ohmic contacts, on both front and rear side, using fluence higher than 1.6 J/cm2 and 3.2 J/cm2, respectively.