Efficiency enhancement in solid state dye sensitized solar cells by including inverse opals with controlled layer thicknesses

• SsDSCs containing TiO2 inverse opals with controlled thicknesses were fabricated.
• An increase of the solar cell efficiency from 2.73% up to 4.25% has been recorded.
• This method can be extended to DSCs using any other dye.

The photoconversion efficiency of dye sensitized solar cells can be enhanced by the incorporation of light management nanostructures such as photonic crystals. Here, we present a facile route to incorporate titania inverse opals into solid state dye sensitized solar cells and report photoconversion efficiency enhancements of up to 56% compared with a model system without the inverse opal. Our approach is based on the precise design of titania inverse opals with a predetermined thickness that can be controlled at the individual layer level. By choosing an inverse opal exhibiting a photonic bandgap which overlaps the absorption bands of the dye, our results show that there is an optimal thickness of the inverse opal structure for maximum efficiency enhancement of the cell. This is the first experimental proof that the thickness of a titania inverse opal plays a pivotal role in cell efficiency enhancement in solid state dye sensitized solar cells.