Comparison of mono- and di-substituted triphenylamine and carbazole based sensitizers @(TiO2)38 cluster for dye-sensitized solar cells applications

This study has been performed to understand the effect of donor strength on photovoltaic performance of Dye-sensitized Solar Cells (DSSCs). For this purpose, Density Functional Theory (DFT) and time domain DFT calculations were carried out. The results reveal that triphenylamine based Dye 2 and carbazole based Dye 4 with di-substituted donor moieties showed red shifted absorption wavelengths, higher oscillator strength and improved electron injection leading to the larger short-circuit photocurrent density (J(SC)). It is expected that these dyes might show larger open-circuit photovoltage (V-OC) as well. These results disclose that di-substitution of the donor moiety would be an efficient strategy to enhance J(SC) and V-OC for better light to power conversion efficiency in DSSCs.