Quantum chemical calculations of phenazine-based organic dyes in dye-sensitized solar cells

In this study, quantum chemical calculations of phenazine-based organic molecules applied in organic dye-sensitized solar cells (DSSCs) have been made and interpreted. Since DSSC molecules work with the electron push-pull system, the sequence of other compounds (2-8) from compound 1 is designed as a donor-pi bridge (weak acceptor)-acceptor (D-pi-A). Later, the studied molecules were expanded from 2a to 8c by lengthening the conjugation with phenyl, thiophene, and furan to the acceptor parts. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations are practiced to investigate all structures and absorption spectra of molecules, respectively. It has been observed that the phenazine-based molecule series are good candidates for DSSCs, both with their band gap and their absorption spectrum results. It can be assumed that changing the HOMO and LUMO energy values of all designed structures according to compound 1 can absorb light in the organic dye-sensitized solar cells and transfer electrons to the conductivity band of TiO2. As a result, it has been resolved that various dyes can be designed for dye-sensitizing solar cells by calculating electronic energies, HOMO-LUMO energies, and absorption wavelengths.