Effects of the terminal donor unit on the photovoltaic parameters of benzocarbazole-based dyes for DSSCs: DFT/TD-DFT investigations

Abstract

In this paper, a computational study on five organic p-conjugated molecules based benzocarbazole (BC) is reported. These new dyes were characterize theoretically by density functional theory (DFT) and time-dependent (TD-DFT) approaches. Different electron side groups were introduced as a terminal donor to investigate their effects on the electronic structure; the HOMO, LUMO, free energy of electron injection (∆Ginject), free energy regeneration (∆Greg), open circuit voltage (Voc), the gap energy and UV–visible absorption spectra analysis of these dyes have been reported and discussed. The calculated results show that dye M3 with phenoxazine as a terminal donor groups can be used as a potential donor of electron in DSSCs, due to its best electronic and optical properties and good photovoltaic.