A novel method for graphene synthesis via electrochemical process and its utilization in organic photovoltaic devices

Graphene nanosheets have been prepared from fine graphite powders by a novel electrochemical exfoliation method using non-volatile sulfate salts. This new method utilizes a stainless steel wire cage and platinum wire electrodes to exfoliate pre-pelleted graphite powders into graphene sheets. Synthesized graphene samples have been characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Raman spectroscopy, and Fourier Transform Infrared (FT-IR) spectroscopy. The obtained supernatant shows a stable suspension in DMF. This suspension was then used in organic solar cells (OSCs) as an additive to poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS). Organic solar cells have been prepared using Indium Tin Oxide (ITO) as the transparent conducting oxide, PEDOT:PSS-Graphene as the hole transport layer (HTL), Poly(3-hexylthiophene-2,5-diyl:[6,6]-Phenyl-C60-butyric acid methyl ester (P3HT:PCBM) as the active layer and Aluminum as the cathode, in ITO/PEDOT:PSS-Graphene/P3HT:PCBM/Al configuration. The photovoltaic cell prepared with graphene as an additive inside PEDOT:PSS exhibited over 66% improvement compared to the reference cells employing pure PEDOT:PSS.