Review on the effect of compact layers and light scattering layers on the enhancement of dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) have attracted significant interest in the scientific community in recent years due to their advantages such as low fabrication cost, facile fabrication and capability to increase the DSSC performance. Up to date, there are a lot of efforts that have been performed to enhance the DSSC performance by introducing compact layers (CLs) and light scattering layer (LSLs) at the TiO2 photoactive layer. The CLs can reduce the recombination effect by preventing direct contact between transparent conductive oxide substrates and redox electrolytes. The CLs can reduce current leakage and generate more photocurrent and voltage, resulting in high DSSC performance. The performance of DSSCs also can be improved via the addition of LSLs. The LSLs must be larger than the titanium dioxide (TiO2) nanoparticles (typical photoanode in DSSCs) to trap more incident light and can excite more electrons, producing high power conversion efficiency. This review will be focused on the modification of the TiO2 photoactive layer by introducing CLs and LSLs to reduce the recombination effect and increase the light scattering effect for enhancing the DSSC performance. This review highlights various approaches and morphologies to prepare the CLs and LSLs using metal oxides and carbon-based materials.