For bulk-heterojunction organic solar cells, the morphology of the blend films highly influence the exciton dissociation and charge transport process. In this work, two novel A-π-D-π-A(A represents the acceptor unit...For bulk-heterojunction organic solar cells, the morphology of the blend films highly influence the exciton dissociation and charge transport process. In this work, two novel A-π-D-π-A(A represents the acceptor unit and D represents the donor unit) backbone structure small molecular electron donors based on two dimensional conjugated naphtho[1,2-b:5,6-b']dithiophene(NDT) with different end alkyl chains, named as NDT-3T-EH and NDT-3T-O, have been designed and synthesized. The photovoltaic property of NDT-3T-O-based device is better than that of the NDT-3T-EH and the best efficiency reaches 7.06%, and the photovoltaic property of NDT-3T-EH reaches 6.11%. The difference in the performance should be attributed to the different morphology and phase separation resulted from the different crystallinity and aggregation ability of two donors. The results demonstrate that the optimized end alkyl chains can be used to design A-π-D-π-A backbone structure small molecular electron donors for smallmolecule organic solar cells.展开更多
基金financial support from the National Natural Science Foundation of China (Nos. 21822503, 21534003, 21125420, 21603044 and 91427302)the Ministry of Science and Technology of China (Nos. 2016YFA0200704 and 2016YFF0203803)+1 种基金the Beijing Nova Program (No. Z17110001117062)the Youth Innovation Promotion Association CAS and the Chinese Academy of Sciences
文摘For bulk-heterojunction organic solar cells, the morphology of the blend films highly influence the exciton dissociation and charge transport process. In this work, two novel A-π-D-π-A(A represents the acceptor unit and D represents the donor unit) backbone structure small molecular electron donors based on two dimensional conjugated naphtho[1,2-b:5,6-b']dithiophene(NDT) with different end alkyl chains, named as NDT-3T-EH and NDT-3T-O, have been designed and synthesized. The photovoltaic property of NDT-3T-O-based device is better than that of the NDT-3T-EH and the best efficiency reaches 7.06%, and the photovoltaic property of NDT-3T-EH reaches 6.11%. The difference in the performance should be attributed to the different morphology and phase separation resulted from the different crystallinity and aggregation ability of two donors. The results demonstrate that the optimized end alkyl chains can be used to design A-π-D-π-A backbone structure small molecular electron donors for smallmolecule organic solar cells.
