Molecular design, electronic structure and optoelectronic properties of vinyl fused monomeric and oligomeric benzothiazoles—A theoretical investigation

Abstract

The organic semiconductors have apprehended a significant role in flexible, thin-film, electronics with different flavors of applications. They are fabricated into electronic devices to enhance their overall performance and efficiency. Optimizing the optoelectronic properties will improve the performance of the device. In this work, a theoretical investigation has been made on vinyl fused monomeric and oligomeric benzothiazole molecules were presented to propose new organic materials for organic electronics. Moreover, fourteen monomeric and oligomeric benzothiazole molecules designed with donors (-N(CH3)2, -OH) and acceptors (-CN, -CF3) to construct D-π-A frames. The DFT and TDDFT methods with B3LYP/6–31+G(d,p) and B3P86/6–311++G(d,p) basis set were employed to elucidate the optoelectronic properties of the 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 optoelectronics. The conclusion of the work reveals that -N(CH3)2:-CN and -CN:-OH substituted oligomers demonstrates significant optoelectronic properties which could be used in optoelectronic devices.