Computational design and experimental investigation of novel thiophene-based organic dyes with N,N-dimethylaminophenyl and morpholinophenyl donors for dye-sensitized solar cells

Abstract

A new series of thiophene-based organic chromophores (4–7 a, b) has been developed through structural engineering of the electron donor (D) group, incorporating N,N-dimethylaminophenyl and morpholinophenyl, and acceptor moieties such as benzonitrile and flurobenzonitrile. Additionally, a π-linkage of phenylthiophene was inserted. The effects of various donating and accepting groups, as well as the spacer, on the geometrical, energetic, absorption, and photovoltaic properties of these sensitizers were investigated using Density Functional Theory (DFT) and Time-Dependent DFT. The sensitizers were optimized in their ground state using selected functional methods. Furthermore, key properties such as absorbance, frequency, energies of Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO), energy gap, dipole moment, and global reactivity descriptors were calculated using quantum chemical calculations. These spectral properties and quantum chemical calculations provide valuable insights into the potential use of these sensitizers in photonic devices. The results obtained from analyzing light harvesting efficiency (LHE), free energy injection (ΔGinj), and open circuit voltage (Voc) demonstrate that these dyes show promising characteristics for future experimental studies and offer guidelines for improving the performance of dye-sensitized solar cells. By employing structural modifications and investigating the electronic properties of these newly developed chromophores, this study contributes to the understanding of their behavior and potential applications in photonic devices. The findings provide a foundation for further experimental investigations and offer valuable insights for the development of more efficient dye-sensitized solar cells.