Synthesis, characterization and exploration of photovoltaic behavior of hydrazide based scaffolds: a concise experimental and DFT study

Solar energy being a non-depleting energy resource, has attracted scientists' attention to develop efficient solar cells to meet energy demands. Herein, a series of hydrazinylthiazole-4-carbohydrazide organic photovoltaic compounds (BDTC1–BDTC7) with an A1–D1–A2–D2 framework was synthesized with 48–62% yields, and their spectroscopic characterization was accomplished using FT-IR, HRMS, (1)H and (13)C-NMR techniques. Density functional theory (DFT) and time dependent DFT analyses were performed utilizing the M06/6-31G(d,p) functional to calculate the photovoltaic and optoelectronic properties of BDTC1–BDTC7via numerous simulations of the frontier molecular orbitals (FMOs), transition density matrix (TDM), open circuit voltage (V(oc)) and density of states (DOS). Moreover, the conducted analysis on the FMOs revealed efficient transference of charge from the highest occupied to the lowest unoccupied molecular orbitals (HOMO → LUMO), further supported by TDM and DOS analyses. Furthermore, the values of binding energy (E(b) = 0.295 to 1.150 eV), as well as reorganization energy of the holes (−0.038–0.025 eV) and electrons (−0.023–0.00 eV), were found to be smaller for all the studied compounds, which suggests a higher exciton dissociation rate with greater hole mobility in BDTC1–BDTC7. V(oc) analysis was accomplished with respect to HOMO(PBDB-T)–LUMO(ACCEPTOR). Among all the synthesized molecules, BDTC7 was found to have a reduced band gap (3.583 eV), with a bathochromic shift and absorption maximum at 448.990 nm, and a promising V(oc) (1.97 V), thus it is regarded as a potential candidate for high performance photovoltaic applications.