Furan-bridged thiazolo [5,4-d]thiazole based D–π–A–π–D type linear chromophore for solution-processed bulk-heterojunction organic solar cells

Abstract

Novel furan-bridged thiazolo[5,4-d]thiazole based π-conjugated organic chromophore (RFTzR) was formulated and utilized for small molecule organic solar cells (SMOSCs). The presence of furan spacer along with two terminal alkyl units significantly improved its absorption and solubility in the common organic solvents. RFTzR exhibited the reasonable HOMO and LUMO energy levels of −5.36 eV and −3.14 eV, respectively. The fabricated SMOSCs with RFTzR (donor) and PC₆₀BM (acceptor) as photoactive materials presented relatively high power conversion efficiency of ∼2.72% (RFTzR : PC₆₀BM, 2 : 1, w/w) along with good open-circuit voltage of ∼0.756 V and high photocurrent density of ∼10.13 mA cm⁻², which might attribute to its improved absorption, electrochemical properties and the presence of strong electron-withdrawing furan moieties.