OPTIMIZATION OF ELECTRONIC STRUCTURE AND OPTOELECTRONIC PROPERTIES OF VINYL FUSED MONOMERIC AND OLIGOMERIC BENZOTHIAZOLES–A QUANTUM CHEMICAL INVESTIGATION

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.