Optimizing scattering layer for efficient dye sensitized solar cells based on TiO2 nanofiber

A one-dimensional nanostructure scattering layer, composed of electrospun TiO2nanofibers with bigger-diameter, is introduced in-situ on top of the photoanode made of smaller-diameter TiO2nanofibers to extend the light path, thereby improving the power conversion efficiency of dye sensitized solar cell. Different configurations are investigated to achieve optimal design for the photoanode. Light trapping effect by the scattering layer is found to be related to the thickness of the photoanode, and the thicker is the photoanode the weaker is the scattering effect. Furthermore, the thickness of the scattering layer in relation to the total thickness of the photoanode needs to be optimized balancing the dye-loading capacity of smaller diameter nanofibers and the light-trapping capacity of bigger diameter nanofibers. A high efficiency of 9.28% is achieved when the optimal thickness of the scattering layer is one seventh of the photoanode thickness of 9.3 μm.