Synthesis, characterization and photovoltaic application of N,N′-bisfluorenyl substituted perylene bisimide

A novel perylene bisimide derivative, N, N′-Bis(9, 9, 9′, 9′-tetraoctyl-bisfluoren-2-yl)-3, 4:9, 10-perylene bisimide (BFPBF), has been successfully synthesized via a condensation reaction. The new compound having a donor–acceptor–donor (D–A–D) structure is soluble in common organic solvents such as chloroform and toluene and thus can be easily processed by wet techniques such as spin-coating. BFPBF is thermally stable with a decomposition temperature (Td) above 430 °C and exhibits a glass transition temperature (Tg) of 160 °C under nitrogen atmosphere. Electrochemical investigation indicates that BFPBF has a LUMO level of −4.07 eV which is similar to that of [6,6]-phenyl C61 butyric acid methyl ester (PCBM). Bulk heterojunction photovoltaic device was fabricated using a blend of poly(3-hexylthiophene) (P3HT) and BFPBF (1:1, w-w) as an active layer and power conversion efficiency of the device was 0.13% under simulated solar light AM 1.5 G (100 mW/cm2).