Investigation of difluorobenzene bridged cross-conjugated benzodithiophene-based small molecules with efficient photovoltaic parameters

The current study focuses on the designing of Benzo[1,2-b:4,5-b′]dithiophene (BDT)-based newly devised chromophores (BDTW1-BDTW4) by the structural alteration of fluorinated BDT2FMeDPA molecule designated as reference (BDTWR) molecule. All newly designed chromophores constitute BDT core, difluorobenzene and diphenylamine, and thiophene linked with distinct acceptor moieties at terminal positions. The introduction of reliable acceptor moieties at peripheral positions can enhance the working efficiency and optoelectronic properties of organic solar cells. A trustworthy DFT and TD-DFT approach was applied to perform the computational characterization of newly planned molecules at CAM-B3LY/6–31 G (d, p). Geometric parameters and optoelectronic properties of tailored molecules (BDTW1-BDTW4) are investigated by equating them with BDTWR. Many important photophysical descriptors such as molecular electrostatic potential (MEP), reorganization energy (RE), ionization potential and electron affinity, transition density matrix (TDM), binding energy (Eb), Frontier molecular orbital (FMO), density of states (DOS), dipole moment and open-circuit voltage of intended molecules are studied to show the expeditious advancement in solar cell devices. Result uttered that among all BDT-based molecules, BDTW3 exhibited the lowest band gap (4.37 eV), highest electron affinity (2.24 eV), highest λ max (467 nm) in dichloromethane (DCM), and highest dipole moment (13.92 D). All architecture molecules (BDTW1-BDTW4) exhibited high VOC than BDTWR, and among all reported molecules, BDTW1 and BDTW3 are characterized by highest theoretically computed V OC value of 3.01 and 2.78 eV because of their low-lying HOMO. BDTW3 exhibited the lowest λ e (0.014 eV), and BDTW4 portrayed the lowest λ h (0.013 eV) signifying its amplified charge mobility. All intended BDT-based chromophores (BDTW1-BDTW4) with newly planned strategy have manifested outstanding outcomes and might be proven as an economic competitor to assemble efficient organic solar cells.