Enhanced Performance of Dye-Sensitized TiO₂ Solar Cells Incorporating COOH-Functionalized Si Nanoparticles

Dye-sensitized solar cells (DSSCs) treated with COOH-functionalized Si (Si-COOH) nanoparticles exhibited a higher short-circuit photocurrent density ( J sc ) and open-circuit voltage than the corresponding untreated DSSC. The enhanced J sc is attributed to the sensitization resulting indirectly from the N719 dye attached to the Si-COOH nanoparticles by intramolecular charge transfer and directly from the Si nanoparticles anchored onto the TiO 2 film. As a result of the improved performance, the overall energy conversion efficiency was increased by 17%, as compared to that for a reference cell without the Si-COOH nanoparticles at 100 mW cm −2 .