Functionalizing organic dye with cross-linked electrolyte-blocking shell as a new strategy for improving DSSC efficiency

Abstract

A simple method used to reduce the electron recombination in dye-sensitized solar cells (DSSCs) is demonstrated. The new dye molecule VTPCA equipped with a thermally cross-linkable styryl group can undergo polymerization during the annealing step of device fabrication to generate an electrolyte-blocking shell, which can impede undesirable electron recombination with the electrolyte. The J_sc, V_oc, FF of the solar cell sensitized with VTPCA are 9.83 mA cm⁻², 0.74 V, and 0.73, respectively, yielding an overall conversion efficiency of 5.31%. The result acquires 31.4% improvement on device efficiency compared to the unmodified device. In addition, with the incorporation of co-adsorbent chenodeoxycholic acid (CDCA) and cross-linkable repair additive 4,4′-divinyltriphenylamine (DVTP), the optimized device with a robust shell shows an overall 46.8% enhancement over the basic model device.