Theoretical design and study on hexamolybdate-based organic-inorganic hybrids with double D-π-A chains for high performance p-type dye-sensitized solar cells (DSSCs)

Abstract

A series of hexamolybdate-based organic-inorganic hybrids containing double donor-π-linker-acceptor chains were studied by using density functional theory and time-dependent density functional theory methods. The energy levels of frontier molecular orbitals, absorption spectra, electronic transition characters and photovoltaic parameters of dyes 1–6 were systematically evaluated. The results show that the absorption spectra are broadened and red-shifted by introducing hexamolybdate and different π-linkers. The absorption spectrum of dye 5 (thiophene as π-linker) has three strong and broad absorption bands in 300–750 nm. The hole injection energy, dye regeneration energy and charge recombination energy of dye 5 are smaller than others, which are advantageous to the hole injection and dye regeneration. The introduction of thiophene (dye 5) in this study is the most effective strategy to improve the absorption and increase the efficiency of dye in dye-sensitized solar cell (DSSC).