By changing the π -linker groups and the anchor unit, six new organic dyes based on phenothiazine, phenoxazine, and phenohydrazine have been created in this work. Density functional theory (DFT) was used to examine their structure, electrical, and photovoltaic properties at the B3LYP/6-31G (d,p) level. In addition, the investigated dyes' charge transfer characteristics and electronic absorption spectrum in the CH 2 Cl 2 solvent were determined using the Time-Dependent DFT at the TD - BHandH/6-31G (d,p) level approach. Frontier molecular orbitals (FMOs), optoelectronic characteristics, and geometry parameters are examples of molecular properties. Through our research, we were able to demonstrate that every dye under study possesses noteworthy intramolecular charge transfer (ICT) capabilities, high light capture efficiency (LHE), and λ max in the range of 285–515 nm, with a range-wide band gap of 1.77–2.31 eV. The developed dyes with triazine, PhON, PhSN, and PhNN, have better geometric and optoelectronic properties than phenyl and -linker dyes. According to the theoretical calculations, these compounds could be exploited as potential sensitizers for DSSC applications. [Display omitted] • Dyes incorporating triazine exhibit nearly planar structures compared with those with phenyl rings. • Notably, the phenylhydrazine-based dye (PhNN) dye exhibits red-shifted absorptions compared to the other dyes. • Examination of the dyes@(TiO 2) reveals favorable adsorption onto the TiO 2 surface (negative adsorption energy). • The energies of FMO for the dyes@TiO 2 exhibit a noticeable shift in stabilization compared to the free dyes. • The analysis indicates that dyes containing triazine (PhON, PhSN, and PhNN) exhibit the highest levels of photovoltaic efficiency. [ABSTRACT FROM AUTHOR]