Quantum Chemical Studies of Sensitizers Designed for Dye-Sensitive Solar Cells

In this study, two different organic dyes with a D-π1-R-π2-A structure were designed from the reference dye E0 with a D-π1-π2-A structure (E3-E4). By adding 2,3-dicyanopyrirazinophenanthrene between the π-bridges on the reference dye E0 and changing the π-bridge, dyes designed to examine the photovoltaic features for use in dye-sensitized solar cell (DSSC) devices were obtained. Various properties of the designed dyes, such as their geometrical structures, absorption spectra, nonlinear optical properties (NLOs), energy levels, boundary molecular orbitals, and some photovoltaic and chemical reactivity parameters, were investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods to improve the performance of Dye-Sensitized Solar Cells (DSSCs). The calculated theoretical results concluded that E4 of the designed dyes can have a high short-circuit current and better power conversion energy (PCE) compared with E0. These results indicate that adding different auxiliary ligands and modifying the π-bridges can effectively improve the photovoltaic performance of the system.