Enhancing of novel D-π-A materials and optimization of photovoltaic performance for organic solar cells

We used density functional theory (DFT) and its time-dependent method (TD-DFT) at the level of the hybrid functional B3LYP and base 6-31G(d,p) to investigate the geometrical, optoelectronic and optical properties of selected organic semiconductor materials based on a Donor-Acceptor (D-π-A) architecture. Our study and design were based on P3HT as donor, furan as π-conjugated spacer, and benzothiadiazole as acceptor with strong potential in the domain of organic photovoltaic materials. In-depth analysis was carried out on the following parameters: HOMO (Highest Occupied Molecular Orbital) and LUMO (Low Unoccupied Molecular Orbital) energies, energy bandgap (Egap), frontier molecular orbitals (FMO), electronic affinity (EA) and ionization potential (IP). Absorption and emission properties were investigated using the the TD-DFT method, revealing broad absorption peaks in the UV-visible range above 715 nm, with well-defined wavelength maxima (λmax), vertical transition energies and transition intensities. A A SILVACO simulation was performed to analyze the photovoltaic efficiency of donor polymers combined with PCBM as an acceptor and an intermediate layer of zinc oxide (ZnO) with the aim of improving energy efficiency. The following electrical parameters were calculated: open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), energy conversion efficiency (η), as well as series resistance (Rs) and shunt resistance (Rsh). The efficiency of 17.73% achieved demonstrates the effectiveness of this adjustment. These positive results suggest the strong potential of these polymers in the field of organic photovoltaics, a sector that is becoming increasingly important for the development of cleaner and more efficient energy solutions.