DFT and TD-DFT Study of Benzodithiophene-Based Donor Materials with Enhanced Optoelectronic Attributes for Organic Solar Cells

Abstract

DFT and TD-DFT methodologies were applied to study seven new donor (T1–T7) compounds based on benzodithiophene (BDT) for organic solar cells (OSCs). The newly designed molecules (T1–T7) were computationally analyzed and compared with reference molecules (TR) to investigate their geometrical, photovoltaic, and optoelectronic properties. These analyses included evaluations of the compounds' frontier molecular orbital (FMO), density of state (DOS), electron density distribution pattern, open circuit voltage (V_oc), absorption spectra, charge mobility, and transition density matrices (TDM). In comparison to other structures studied, the optoelectronic properties of the suggested structure T1 in chloroform solvent were the most improved, having a smaller band gap (3.75 eV), a greater maximum absorbance (543 nm), and lower excitation energy (2.28 eV). In comparison to TR, V_oc is high for every constructed molecule which results significant efficiency of organic solar cell. As a result, every computed property strongly supports the potential of our proposed molecules in solar energy applications.