3. Results and Discussion:
The fully relaxed structures of six photosensitizer dyes were attained at different levels of theory hybrid-B3LYP, GGA-PBE and SCC-DFTB. The excitation spectra and photoinjection in dye-(TiO2)96system for all dyes was studied in vacuum and solvents for improving the performance of DSSC. The results on excitation spectra and optical transitions in D1, D2 and D3 have been reported elsewhere [20]. However, the description involving these dyes is given here for sake of completeness with addition of photoinjection as well as solvation effects involving these three dyes. The magnitude of molecular dipole moment, calculated with analytic integration using PBE were 1.680 for D1, 2.195 D2, 2.246 for D3,2.001 for D1A,2.027 for D2A and 1.769 for D3A. In what follows, the calculated results and discussion to shed light on photoinjection in all 6 dyes are described.