Paper Title
Density Functional Theory Investigations on the Electronic and Optical Properties of Vinyl Based Systems
Abstract
Organic solar cells essentially needed lower band gap conjugated polymers for massive sunlight cultivation.
Tuning electron rich and electron deficient units in a conjugated polymer can ease to reduce the band gap with high power
conversion efficiency can be reached with this altered D-A units. Accordingly, we constructed seven methodically tuned
conjugated polymers I-VII, where a vinyl-pyridine electron moiety is linked with each of seven fused ring electron rich
moieties (auxochrome altered di-thiophene Dione). The calculation shows that the monomer moieties I and II, have lower
band gaps and wide range of absorption solar light among the seven systems. An electron donating group of amine and
withdrawing group of carbonyl is not only allows to lower the LUMO and increase the HOMO energy levels, but also
altered the solar light absorption range. From the compared results of monomer I and VII given an idea to understand the
role of hetero atoms on the conjugated donor-acceptor units to be lowered the band gap as also increase the range of the
visible light absorption. This study revealed introduces and choose the position of the hetero atoms affect the optoelectronic
properties of the copolymers. This remarkable study furnishes an idea to synthesis of appropriate co-polymers to well
optoelectronic devices.
Keywords— TD-time dependent, DFT-density functional theory, Organic photovoltaic cell, pyridine, band gap, dihedral
angle.