Laser Patterning of Epitaxial Graphene for Schottky Junction Photodetectors

Large-area patterning of epitaxial graphene for Schottky junction photodetectors has been demonstrated with a simple laser irradiation method. In this method, semimetal-semiconductor Schottky junctions are created in a controllable pattern between epitaxial graphene (EG) and laser-modified epitaxial graphene (LEG). The zero-biased EG-LEG-EG photo-detector exhibits a nanosecond and wavelength-independent photoresponse in a broad-band spectrum from ultraviolet (200 nm) through visible to infrared light (1064 nm), distinctively different from conventional photon detectors. An efficient external photoresponsivity (or efficiency) of similar to 0.1 A.W-1 is achieved with a biased interdigitated EG-LEG-EG photodetector. The fabrication method presented here opens a viable route to carbon optoelectronics for a fast and highly efficient photoconductive detector.