Electrospinning of TiO2 for dye sensitized solar cells

Dye adsorption on TiO2 and electron transport in TiO2 film are the two critical elements in determining the dye sensitized solar cell (DSSC) efficiency. Increasing dye adsorption which in turn increases the light harvesting is usually achieved by using nanoporous or nanoparticle TiO2 films. Electron transport is determined by the inter-particle resistance of TiO2 film. Electrospinning is a viable method for forming porous structure materials with high surface area. In this study, it was found that electrospinning alone is not able to achieve good solar cell performance due to the low electron transport caused by the pores in the TiO2 film. To increase dye adsorption without sacrificing the electron transport, a hybrid bilayer TiO2 structure with each layer prepared by different methods, blade coating and electrospinning was explored. This hybrid structure was compared with the single doctor bladed structure. A significant increase of Jsc was observed for the bilayer structure which resulted in an improvement of solar cell efficiency of 30% (from 1.6% to 2.11%).