Study on optical properties of graphene-TiO2 nanocomposite as photoanodes layer in dye sensitized solar cell (DSSC)

Abstract

Dye Sensitized Solar Cell (DSSC) using titanium dioxide (TiO2) has begun to play a significant role in future solar energy since it is known as cost effective and highly efficient. DSSC is the third generation of photovoltaic cells that have been widely investigated as a promising replacement of current commercial solar cell. However, the highest efficiency of DSSC still has not achieved the minimum requirement so that it can be commercialize. Much research has been done to improve DSSC performance by focusing on photoanodes layer. In this study, graphene was employed into TiO2 photoanode to increase the efficiency and to enhance the performance of dye sensitized solar cell. Four different samples of nanocomposites paste were prepared by varying the graphene composition of 0.00, 0.30, 0.50 and 0.70 wt%. The prepared samples were coated on Fluorine-Doped Tin Oxide (FTO) conductive glass substrates by a doctor blade method and annealed at 450oC for 30 minutes. The morphology and structure of the graphene-TiO2 nanocomposites layer were characterized by using Field Emission Scanning Electron Microscope (FESEM). The optical properties were studied by using UV-visible spectroscopy. Based on the result show that addition of graphene into TiO2 have provide larger surface area compared to pure TiO2. The optical properties of Graphene-TiO2 nanocomposites also improved as the fundamental of absorption edge has shifted toward longer wavelength and reduce the optical band gap.