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 effi-ciency (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), op-tical properties, open-circuit voltage, transition density matrix (TDM), Frontier molecular orbital (FMO) align-ment, and hole and electron reorganization energies have all been studied for these materials. PEH8 has an excellent absorbance (lambda max) 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.

Automated summary

Si-OMeTPA is gaining attention as a potential hole transport material in PSCs due to its energy tuning capabilities, strong absorption, and high PCE. This study introduces eight new donors (PEH1-PEH8) with 4,4-diphenyl-4H-silolo[3,2-b:4,5-b'] dithiophene as the central-core unit and explores their electronic and optical performance. Theoretical characterization using DFT and TD-DFT computations reveals the photo-physical and optoelectronic properties of these materials, including DOS, optical properties, open-circuit voltage, TDM, FMO alignment, and reorganization energies. PEH8 exhibits excellent absorbance and an optical band gap of 0.91 eV. Additionally, the charge shifting at the donor-acceptor interface of PEH8/PC61BM is investigated. This research is crucial for developing efficient PSCs with suitable photovoltaic molecules for light harvesting and charge transportation.