Fabrication of graphene-ZnO heterostructure-based flexible and thin platform-based UV detector

This work presents the performance evaluation of Graphene/ZnO Schottky junctions grown on flexible indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates. The fabricated structures include chemical vapour deposition grown graphene layer on ITO-coated PET substrates. Polymethyl methacrylate assisted transfer method has been employed for the successful transfer of graphene from Cu substrate to PET. The smaller D-band intensity (1350 cm(-1)) compared to G-band (1580 cm(-1)) indicates good quality of carbon lattice with less number of defects. High-quality ZnO has been deposited through RF sputtering. The deposited ZnO with grain size 50-95 nm exhibited dislocation densities of 1.31270 x 10(-3) nm(-2) and compressive nature with negative strain of - 1.43156 GPa. Further, the electrical and optical characterization of the devices has been done through device I-V characterization and UV detection analysis. The UV detection capability of the device has been carried out with the aid of a UV-lamp of 365 nm wavelength. The fabricated graphene/ZnO photodetector showed good response to UV illumination. The device performance analysis has been done through a comparison of the device responsivity and detectivity with the existing detectors. The detectivity and responsivity of the fabricated detectors were 7.106 x 10(9) mHz(1/2) W-1 and 0.49 A W-1, respectively.