Novel N-heteroacene small molecules as electron donors for organic bulk heterojunction photovoltaics

Abstract Two N-heteroacene small molecules, P2BT and P2B2 T, with 2,1,3-benzodiathiazole end-capped N-heteroacene unit as the central building block have been designed and synthesized for bulk-heterojunction solar cells. Single-junction devices based on P2B2 T:PC 71 BM have achieved an impressive power conversion efficiency of 7.16% without any special treatment, which is the record efficiency among the N-heteroacene-based photovoltaics.