Synthesis and characterization of bay substituted perylene diimide small molecule for organic solar cell application

Abstract

We report the synthesis of N,N′-Bis(hexyl)-1,7-di(thiophenyl)perylene-3,4:9,10-tetracarboxylic acid diimide (T-PDI-H) based small molecule by Suzuki coupling method for organic photovoltaic (OPV) application. The synthesized small molecule was confirmed by FT-IR and NMR techniques. The T-PDI-H showed broad and strong absorption in the UV-Visible region. From UV-Visible spectra we observed a low optical band gap (Eoptg) of 1.96 eV for T-PDI-H. From the cyclic voltammetry, the calculated HOMO, LUMO and electrochemical band gap (Eeleg) for the small molecule was −5.77, −3.44 and 2.33 eV respectively. Thermogravimetric analysis was employed to elucidate the thermal stability of T-PDI-H small molecule, it showed good thermal stability up to 400 °C. The preferred property for the high power conversion efficiency (PCE) OPV device, molecule must possess broad and strong absorption in the UV-Vis region, low band gap, and high thermal and environmental stability. T-PDI-H small molecule might satisfy the above standards with the chance to give maximum power conversion efficiency (PCE).