Abstract:
Organic semiconductors are new important technologies for large-area and flexible thin-film
electronics. They are deposited into electronic devices to enhance their overall performance
and efficiency. Therefore, studying the electronic and optoelectronic properties of these
materials is required for the effective optimization of devices. In this work, a theoretical study
based on vinyl fused monomeric and oligomeric benzothiazole molecules were presented with
the aim of proposing new organic materials for organic electronics. Moreover, fourteen
monomeric and oligomeric benzothiazole molecules with donors (-N(CH3)2, -OH) and
acceptors (-CN, -CF3) group have been designed. The quantum chemical methods such as
density functional theory (DFT) and time dependent density functional theory (TD-DFT)) were
applied with B3LYP/6-31+G(d,p) and B3P86/6-311++G(d,p)basis set, respectively to
elucidate electronic and optoelectronic properties of designed molecules. Using these
methods, several parameters such as the geometry, polarity (dipole, polarizability
hyperpolarizability), FMO analysis, charge transport properties, molecular electrostatic
potential (MEP), excited state properties, and further molecular electronic structure
properties of the designed molecules have been computed. The results obtained confirmed that
the geometric parameters, HOMO-LUMO gap, ionization potential (IP), electron affinity
(EA), reorganization energies (λ), polarizability, hyperpolarizability, and absorption and
emission spectra of the designed candidates can be significantly tuned by substitution of
different donor-acceptor groups and extending the benzothiazole ring and these compounds
can be used to make efficient OLEDs. The final conclusion of the work revels that -N(CH3)2:-
CN and -CN:-OH substituted oligomers showed significant optoelectronic properties which
could be used in OLED devices.
