3:15 PM - 3:30 PM
[20p-231C-5] Effect of the molecular orientation of PC61BM on performance of organic photovoltaics
Keywords:molecular orientation, fullerene acceptor, donor/acceptor interface
We investigated the effects of PC61BM’s orientation on ITO/PEIE/PC61BM/6T/MoOx/Al structured OPVs, where the orientation of PC61BM was controlled by thermal annealing. When 6T contacts with the side chain of PC61BM, VOC increases by a factor of 1.4 in comparison to the direct contact of 6T with C60 backbone of PC61BM. The multiple analyses with photoelectron spectroscopy, electroluminescence, and external quantum efficiency suggest that the energy of the charge transfer states increases in such an interfacial geometry and carrier recombination is suppressed by the presence of the side chain of PC61BM at the donor/acceptor interface.