The effect of π-spacer on D-A'-π-a system organic dyes for dye-sensitized solar cells (DSSCs) technology: a computational approach”

Abstract The globe is consuming more energy as a result of population growth and economic development. One of the most important forms of renewable energy for human usage is solar energy. By modifying the π-spacers, four D-A'-π-A of novel organic dye molecules (D1–D4) have been created in this study. To evaluate the optoelectronic capabilities and photovoltaic qualities of four D-A'-π-A new organic dyes created molecules, density functional theory (DFT) and time-dependent DFT (TD-DFT) theory methodologies through the B3LYP and 6-311G basis set have been employed. To ascertain the effect of developed π-spacer on enhancing intramolecular charge transfer (ICT) and enhancing light-absorbing capacities, a number of crucial factors, including molecular geometry, energy bandgap and light-harvesting efficiency (LHE), have been studied. Based on the available data, D4 outperforms the other four developed organic dye molecules, with energy bandgap of 1.4896 eV and 1.4253 eV for gas and solvent phase, respectively, regeneration driving forces (ΔGreg) of 0.0469 eV and 0.0300 eV for the gas phase and solvent phase, respectively, and open-circuit voltages (Voc) of 0.6427 eV and 0.5953 eV for the gas phase and solvent phase, respectively. Additionally, the maximum absorption wavelengths (𝜆max) for the gas phase and solvent phase are 932.03 nm and 1013.81 nm, respectively. Consequently, it was found that the D4 dye molecule was a more promising option for the use of dye-sensitized solar cells (DSSCs) technology hence advised for more practical research to provide efficient advancements in the D-A'-π-A system organic dye for the production of sustainable energy.