Molecular engineering strategy and optoelectronic properties of diaminobenzene-thiazole π-conjugated small donor molecules for high-performance organic solar cells

Abstract

In this current study, the π-conjugated oligomers based on Thiazole units have been designed to understand the interaction of molecular orbitals and the influence of the substituents on the energetic HOMO-LUMO gap to build highly π-conjugated nanostructures. Their strong π-conjugated insight was also evidenced in gas phase through the photovoltaic properties using B3LYP/6-31G(d,p) level of theory for potential applications in organic electronic devices. Our research indicates geometries optimized structures, FMOs and chemical parameters were determined to predict optical properties of all oligomers. The results demonstrate that thiazole unit’s addition improved absorption above 400 nm at first excited states. The open-cicruit voltage Voc have been decreased from 2.22 V to 1.26 V in M1-a to M1-d. Whereas, LHE values was increased from 0.404 to 0.986 in M2-a to M2-d. All designed molecules have shown the enhanced optoelectronic characteristic that is plausible reason for their potential photoactive use in Organic Photovoltaics (OPVs) devices efficiencies.