Abstract:
In all solar cells and other devises, which harvest sun lights, charge transfer play a important role. The theoretical study of charge transfer using
quantum mechanics is still inadequate. In this thesis we have done some
theoretical investigation on charge transfer using time dependent density
functional theory(TDDFT). Acceptor and donor are two important parts in
charge transfer mechanism. The Polycyclic Aromatic Hydrocarbons (PAHs)
molecules which can work as a donor in charge transfer mechanism also play a
important role in Astrophysics. So we investigated the PAHs using TDDFT
and extracted absorption spectra, for different PAHs varying in size, and
match the results from pre-calculated absorption spectra(using TDDFT).
Anthraquinone and its derivative are commonly use as dyes. Due to presence of anthraquinone ring, anthraquinone and its derivative make it eligible
to work as acceptor. 1,5-diaminoanthraquinone(1,5-DAAQ) molecule which
show the broad band observed in the visible region is due to the intramolecular charge transfer between the amino group and the anthraquinone ring.
We calculated this broad band in visible region though our pick position
doesn’t match with expeimental one. Using this CAM-B3LYP range separated exchange correlation functional we have shown charge oscillation in
TCNE dimer and TCNE with Benzene systems where in each calculation
one of the fragment of system has one extra electron.
