Head-to-tail bonded perylene bisimide(PBI)dyads with different branched alkyl chains substituted at the terminal imide position show various stacking modes,which results in different effects on the excitonic processes...Head-to-tail bonded perylene bisimide(PBI)dyads with different branched alkyl chains substituted at the terminal imide position show various stacking modes,which results in different effects on the excitonic processes and electron transportation.The dyad bearing branched alkyl chains with the branching sites close to the imide positions forms homogeneously amorphous state,while with branching sites being away from the imide positions the PBI core tend to stack with multiple modes.There are fewer energy trapping sites in the homogeneously amorphous state,but in the multiple stacking system the strongπ-πinteractions give more trapping sites.Our study demonstrates that the aggregation state of PBI-based acceptors plays an important role in the performances of organic solar cells(OSCs).Multiple stacking needs to be diminished to avoid the constrained exciton dissociation and retarded charge transport in the active layer.展开更多
文摘Head-to-tail bonded perylene bisimide(PBI)dyads with different branched alkyl chains substituted at the terminal imide position show various stacking modes,which results in different effects on the excitonic processes and electron transportation.The dyad bearing branched alkyl chains with the branching sites close to the imide positions forms homogeneously amorphous state,while with branching sites being away from the imide positions the PBI core tend to stack with multiple modes.There are fewer energy trapping sites in the homogeneously amorphous state,but in the multiple stacking system the strongπ-πinteractions give more trapping sites.Our study demonstrates that the aggregation state of PBI-based acceptors plays an important role in the performances of organic solar cells(OSCs).Multiple stacking needs to be diminished to avoid the constrained exciton dissociation and retarded charge transport in the active layer.
