Molecular Modelling, Optical and Electrochemical Properties of Novel 3-Arylazo-thieno[3,2-b]pyranone for Photovoltaic Application

Three 3-arylazo-thieno[3,2-b]pyranone dyes HTM1-3 have been synthesized by cyclocondensation of ethyl 2-arylazo-(2-phenylthiocarbamoyl)acetate derivatives with ethyl 4-chloro-3-oxobutanoate in ethanolic sodium ethoxide solution. IR, H-1 and, C-13 NMR, and mass spectra have confirmed the structure of dyes. The impact of substituents (methyl, methoxy and chloride) on physical, chemical and optoelectronic properties of the synthesized dyes has been studied. Optical properties such as extinction coefficient, photoluminescence and optical bandgap of thin films have been studied. The optical energy gap has been computed in the range of 1.97- 2.18 eV. Thermal analysis, molecular modelling and electronic energy levels have been investigated. Typically, these small molecules exhibit promising charge carrier mobility and are proposed to be strong candidates for p-type semiconductors (hole transport layer). Overall, because of their excellent optical absorption, appropriate energy-level alignment and favorable molecule packing, the prepared thienopyran materials could be a good choice for solar cell applications and light-harvesting capacity.