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.