Designing and theoretical study of fluorinated small molecule donor materials for organic solar cells

A recently synthesized photoactive donor named fluorinated thienyl–substituted benzodithiophene (DRTB-FT), modified with four novel end capped acceptor molecules, has been investigated through different electrical, quantum, and spectrochemical techniques for its enhanced electro-optical photovoltaic properties. DRTB-FT was connected to 2-methylenemalononitrile (D-1), 2-methylene-3-oxobutanenitrile (D-2), 2-(2-methylene-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (D-3), 3-methyl-5methylene-2-thioxothiazolidin-4-one (D-4) as terminal moieties. The architectural D-1 D-3 molecules owe reduced optical band gap of 2.45 2.28 eV benefited from A-D-A configuration have broaden maximum absorption (λmax) at 617 602 nm in polar organic solvent (chloroform). Reduced sets the ease absorption. Reorganization energy electron (λe) molecule (0.00397 eV) smaller among all which disclosed greater mobility conducting electrons (ICT). Larger values dipole moment (μ) (5.939 Debye) (3.661 comparison R indicated solubilities targeted molecules. Among tailored showed lowest binding 0.25 phase 0.08 gaseous phase. voltaic strength designed examined respect fullerene derivative (PC61BM) exposed that is best choice achieving higher PCE. TDM (transition density matrix), DOS (density states) analysis, energies were estimated MPW1PW91/6-31G (d, p) level DFT functional theory).