Computational modeling of non-fullerene donor based on indacenodithiophene with amplified optoelectronic attributes for organic solar cells

Abstract

Over the past decade, organic solar cells (OSCs) using electron-acceptor and electron-donor materials have demonstrated significant potential in advanced optoelectronic applications. We developed seven new organic donor molecules (ID1−ID7) based on highly fused indacenodithiophene by modifying the end group of a reference molecule. Using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) with the MPW1PW91 functional, CPCM solvation model, and 6-311G(d,p) basis set, we evaluated the molecules' absorption, excitation, and oscillator strengths. The study assessed key properties, including HOMO/LUMO energy levels, energy gap (E_g), density of states (DOS), dipole moment, transition density matrix (TDM), molecular electrostatic potential (MEP), open-circuit voltage (V_OC), binding energy (E_b), and power conversion efficiency (PCE). The results showed that the new compounds outperformed the reference IDR in photophysical, photovoltaic, and electrical properties. Notably, ID4 excelled with the lowest E_g (1.74 eV), highest λ_max (874 nm), lowest E_x (1.4179 eV), best PCE (15.48 %), high FF (0.90), normalized V_OC (48.73), and absolute V_OC (1.26). These compounds, with their strong electron and hole transport mobilities, are promising for commercial applications. Further research into their properties could enhance the development of efficient photovoltaic organic materials.