A study of the photoresponse in graphene produced by chemical vapor deposition

The results of experiments aimed at fabricating and studying the properties of photodetector structures based on single-layer graphene produced by chemical vapor deposition are presented. The configuration of a Ta$_{2}$O$_{5}$ vertical microcavity with a resonance wavelength of about 850 nm and a lower dielectric SiO$_{2}$/Ta$_{2}$O$_{5}$ distributed Bragg reflector is taken as the base structure. The conditions for the transfer and fabrication of mesas in the graphene layer on the microcavity surface are optimized. The diagnostics by Raman spectroscopy of the structural quality of graphene after fabrication of the mesas in the graphene layer and contact pads are indicative of the single-layer structure of graphene with a low intensity of features in its spectrum, responsible for imperfection of the structure. The photocurrent is measured under local optical pumping.