The Synthesis And Properties Reaserch Of Novel Fulleropyrrolidines For Acceptor Materials

Fullerenes show special photoelectricity properties because of its cage shape structure since the first discovery and separation. Normally, high power conversion efficiency (PCE) can be obtained by the device based on the bulk heterojunction (BHJ) structures, which use fullerenes as acceptor materials and a series of conjugated polymers as donor materials. In this framework, numerous donor-acceptor π-conjugated copolymers with the wide absorption and low bandgap have been synthesized to tune energy levels matched with acceptors, resulting in the great improvement of the light-electrical conversion efficiency. In contrast, less attention has been paid to developing n-type acceptor, the excellent acceptors of n-type C60derivatives include several requirements, such as the suitable solubility, energy levels well-matched with donors, and wide absorption bands.In this paper, we designed and synthesized six modeling compounds via Prato reaction, including ThC6o, PhC60, PyC60, PFThC6o, OPFThC60and PF-co-PC60. The results show that some of target compounds could be well-used as acceptor materials in solar cell device through the performances tests of absorption, thermal gravimetic analysis, cyclic voltammetry, atomic force microscope, scanning electron microscope and others.First, the three compounds of PhC60, PyC60, ThC60exhibit different solubility. PhC6o and PyC60have a limited solubility in toluene, In contrast, ThC60possess better solubility in tetrahydrofuran, toluene, dichloromethane. The absorption spectra of the three compounds closely correspond to C60-The LUMO energy levels of ThC60are higher than that of PGBM. The PCE of the devices with ThC60as acceptors is0.79%.Seconed, PFThC6o has a limited solubility in toluene, OPFThC60possess better solubility in in common organic solvents. Therefore, OPFThC60is more soluble than PFThC60, probably owing to the existence of alkyloxy groups, and octyloxy phenylfluorenyl moieties into ThC60changes phase separation morphology. Furthermore, the results show that the morphology quality using fulleropyrrolidine derivatives as acceptors is completely matched with the PCE of bulk heterojunction solar cells. The PCE of the devices with OPFThC60as acceptors is2.80%Finally, we got double cable type polymers with polyfluorene as main chain, and linked fullerenes with pyrrole ring. The polymer formed a hole-transport passway in the polymer, and provided the electronic transmission in fullerenes. It energy level closely correspond to polyfluorene. It has limited solubility in common organic solvents. We observed the microstructure, and found the porous shape structure in materrial internal.The fulleropyrrolidines are promising n-type organic semiconductors for the application of BHJ solar cells.