| 초록 |
9,9'-Bifluorenylidene (9,9'BF) was promising structure of non-fullerene-type electron acceptors for bulk-heterojunction polymer solar cells (PSC). We synthesized new 9,9'BF derivatives, 2,2',7,7'-tetra(9,9-diethyl-9H-fluorene)-9,9'-bifluorenylidene (TFBF). TFBF was synthesized from 2,7-di(9,9-diethyl-9H-fluorene)-9H-fluoren-9-one by reductive dimerization using Lawesson’s reagent. The measured optical band gap, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of TFBF were 2.32, 5.81, and 3.49 eV, respectively. The photoluminescence (PL) spectra of P3HT solution in chloroform were measured at different TFBF concentrations. The PL intensity of the P3HT solution decreased upon increasing the TFBF concentration. P3HT based photovoltaic devices were fabricated using TFBF as electron acceptor. TFBF possessed relatively high LUMO level promising the high Voc comparing the PC60BM devices (~0.65 V). |
