Theoretical modification of the γ-mangosteen as sensitizer in dye-sensitized solar cell (DSSC) using rhodanine-3-acetic acid as electron withdrawing group

Effects of rhodanine-3-acetic acid as an electron-withdrawing group on γ-mangosteen for DSSC sensitizers have been investigated theoretically using the DFT-TDDFT method. The rhodanine-3-acetic acid bonded on the O3 atom of the γ-mangosteen according to its Mulliken charge. The results show that the LUMO electron density of the modified molecule is localized on the rhodanine-3-acetic group. This position facilitates the electron’s injection into the semiconductor. It is supported by the |VRP| of the modified molecule, which is higher (0.83 eV) than the |VRP| of γ-mangosteen (0.74 eV). However, the electron injection driving force of γ-mangosteen (ΔGinject = -2.11 eV) is more spontaneous than the modified molecule (ΔGinject = -1.15 eV). The obtained spectra show a bathochromic shift for the modified molecule to the visible light region (345 nm to 441 nm). This absorption is under the sensitizers requirements of the DSSC. However, its intensity is still weak, so the LHE value of the modified molecule (3.25 x 10−2) is lower than the LHE γ-mangosteen (7.24 x 10−2). Our data indicate that modification of γ-mangosteen using rhodanine-3-acetic acid did not significantly increase the efficiency of DSSC.