Effect of Photoanodes on the Performance of Dye-Sensitized Solar Cells

Abstract

Dye sensitized Solar cell (DSSC) is a photo-electrochemical system which converts solar energy into electrical energy. In the present era DSSCs takes so much attention because of their considerably high efficiencies at a comparably low production cost. The nanostructured electrode plays a vital role in device properties. Originally, the nanostructured TiO₂ were widely used as DSSC electrodes. Further, nanostructured ZnO has shown a great deal of research interest as the electrode material in DSSCs due to some of its fascinating properties. Compared to other semiconductors, it has unique properties such as large exciton binding energy, wide band gap, high breakdown strength, cohesion and exciton stability. In this paper, the construction and electron transport mechanism of DSSCs devices are described and a comparison of performances of DSSCs fabricated with ZnO or TiO₂ photo electrodes was made in terms of its device parameters. This is further correlated with the band structure & density of states (DOS) of ZnO and TiO₂ using Density functional theory (DFT) and finally the photovoltaic performance of ZnO and TiO₂ based DSSCs was discussed to elucidate the differences.