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Abstract

Organic photovoltaic (OPV) devices show promising as the next‐generation renewable energy source. Currently, the non‐radiative charge recombination induced energy loss is considered to be a major reason for the low device efficiency. This can be further attributed to the use of donor:acceptor (D:A) heterojunction structures, which resolves the high exciton binding energy induced low charge generation issue, but introduces low emissive charge transfer states. In this work, we assess the necessity of D:A heterojunction, and demonstrate that the high‐performance D:A heterojunction‐free OPV device is possible when both photo‐induced spontaneous polaron generation and good ambipolar charge transport are realized. Moreover, the D:A heterojunction‐free structure exhibits much less non‐radiative charge recombination and more stable morphology for high performance, and probably becomes the next game‐changer in OPVs. More details are discussed in the article by Zuo et al. on page 252—258.image