Quantum chemical study of symmetricalnon-fullerene acceptor chromophores for organic photovoltaics

Abstract

It is well reported that the fused ring acceptor modification can be an effective method for improving the optoelectronic and photovoltaic properties of organic materials. The addition of acceptor groups to a core can enhance its electron-withdrawing ability, resulting in improved charge transport and higher power conversion efficiencies in organic solar cells (OSCs). Thieno[3,2-b]thiophene, and diketopyrrolopyrrole are commonly used groups in OSCs due to their powerful electron-withdrawing capabilities and well-established synthetic protocols. Their incorporation into donor–acceptor systems has been shown to enhance the materials absorption spectra, increase the open-circuit voltage (VOC), and improve device performance. Following integrating several acceptor groups onto the recently synthesized core based on thieno[3,2-b]thiophene, and diketopyrrolopyrrole, we have created six novel electron donors (BDPTM1-BDPTM6) with interesting optoelectronic and photovoltaic properties. It is indeed common practice to use computational methods such as density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to investigate the optoelectronic and photovoltaic properties of newly created molecules. These methods allow researchers to obtain crucial parameters such as the HOMO and LUMO energies, energy gap (Egap), frontier molecular orbital alignment, density of states, molecular electrostatic potential, absorption maxima (λmax), excitation energy (Eex), binding energy and transition density matrix…… Among all the designed compounds, BDPTM3 exhibited the lowest energy bandgap (1.63 eV) with bathochromic shift of 921.610 nm in Dichloro-methane and 852.242 nm in gaseous phase. BDPTM2 displayed the highest dipole moment (µtot) at 7.557 eV, BDPTM5, and BDPTM6 demonstrated consistent linear polarizability〈α〉 at 191.612 × 10−22 esu and 196.2823 × 10−22 esu respectively. Notably, BDPTM6 calculated the highest frst hyperpolarizability βtot at 583.849 × 10–30. Based on the results obtained from the theoretical investigation of the optoelectronic and photovoltaic properties of the developed molecules, it may be possible to recommend them as better candidates for use in organic solar cells (OSCs).