Introduction of CaCO۳ as Electron Recombination Barrier Layerin TiO۲-based Dye-Sensitized Solar Cell

Calcium carbonate (CaCO۳) is an effective material for surface modification in TiO۲-based dye-sensitized solarcells (DSSCs). Its higher conduction band position compared to TiO۲ helps reduce electron recombination rates,and its elevated isoelectric point promotes increased dye adsorption. It is crucial to control the thickness of theCaCO۳ layer to less than ۳-۱۰ nm, as tunneling phenomena cannot occur when the insulating layer exceeds ۱۰nm in thickness. In this study, the CaCO۳ layer was deposited using the spin-coating method. Additionally, intwo samples, the second TiCl۴ treatment was omitted during DSSC preparation to assess its impact on thephotovoltaic properties. The results indicate that while the deposition of CaCO۳ enhances the photocurrent ofthe DSSCs, it simultaneously reduces the fill factor. However, applying the TiCl۴ treatment both before andafter CaCO۳ deposition improves the fill factor, leading to greater efficiency compared to the untreatedsamples. Specifically, sample TT۳CT achieved an efficiency of ۷.۹۸%, while the neat sample reached ۷.۵۸%efficiency.

Keywords:

DSSC , Surface Modification , Recombination Barrier Layer , Calcium Carbonate