Hydrogen exfoliated graphene as counter electrode for dye sensitized solar cells

In the present work, we demonstrate the use of few layered Graphene sheets (HEG) synthesized by hydrogen induced exfoliation technique as a novel counter electrode material for dye sensitized solar cells (DSSCs). The presence of wrinkles and low oxygen content gives a high surface area and good electrical conductivity to HEG, making it superior to other graphenes. Electrochemical impedance spectroscopy studies were carried out to determine the catalytic activity of HEG towards tri-iodide reduction. The effect of annealing temperature on HEG counter electrode was also studied. The DSSC fabricated with HEG as counter electrode shows excellent current density, comparable to that of Pt counter electrode and exhibits a power conversion efficiency of ∼ 3.6 % under one sun illumination. © 2011 IEEE.