Designing of silolothiophene-linked triphenylamine-based hole transporting materials for perovskites and donors for organic solar cells-A DFT study

Si-OMeTPA is receiving a lot of interest as potential hole transport materials in perovskite solar cells (PSCs) because of their wide range of energy tuning, strong absorption capacity, and excellent power conversion efficiency (PCE). This work includes eight new donors (PEH1-PEH8) containing 4,4-diphenyl-4H-silolo[3,2-b:4,5-b']dithiophene as the central-core unit has been effectively developed and then theoretically described to probe their electronic and optical performance. These innovative (PEH1-PEH8) materials had lower Eg and more significant extinction coefficients, implying superior phase inversion geometry during sandwich structures. The complete theoretical characterization of these proposed (PEH1-PEH8) and reference (PEH) molecules has been achieved by using quantum chemistry techniques. Density functional theory (DFT) and time-dependent (TD-DFT) computations have explored the photo-physical and optoelectronic properties. The density of states (DOS), optical properties, open-circuit voltage, transition density matrix (TDM), Frontier molecular orbital (FMO) alignment, and hole and electron reorganization energies have all been studied for these materials. PEH8 has an excellent absorbance (λmax) of 699.65 nm and an optical band gap of 0.91 eV. Furthermore, a comprehensive investigation of PEH8/PC61BM has shown the fantastic charge shifting at the donor-acceptor interface. As a result, our suggested strategy is required for developing suitable photovoltaic molecules for proficient PSCs that can be employed as light harvesters and electron and hole transporter.