Electrically reduced graphene oxide for photovoltaic application

We report Electrically reduced graphene oxide (GO) and n-type Si heterostructure junction-based photovoltaic cell. The transition of the insulating properties of GO to that of semi-conducting was achieved by applying electric voltages using 5, 10, and 15 V biasing. The photovoltaic deviceI—Vcharacteristics corresponding to the increasing (5–15 V) reduction voltages, obtained on exposure of 25 mW/cm2visible light, showed approximately same fill factor with increased efficiency. The maximum efficiency of 1.12% was observed under ultraviolet light exposure for photovoltaic cell consisting GO reduced using 15 V reduction voltage. GO was synthesized using the modified Hummers’ technique and characterized by X-ray diffraction (XRD), ultraviolet—visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The GO characteristic XRD peak corresponding to plane (001) was observed at 9.16°. The UV-Vis spectrum for GO displayed an absorption peak at 228.5 nm, and the corresponding Tauc plot analysis provided a band gap of 4.74 eV. The FTIR analysis showed presence of C=O (1713 cm−1), C=C (1627 cm−1), C—OH (1418 cm−1), C—O–C (1252 cm−1), C—O (1030 cm−1), and C—H (827 cm−1) functional groups in GO.