Reducing burn-in loss in organic photovoltaics by enhancing the morphological and interfacial stability (Conference Presentation)

With rapid advances in the development of new conjugated polymers, non-fullerene acceptors, the power conversion efficiency (PCE) of OPVs has been increased over 14%. However, a major drawback for the commercialization of OPVs is their long-term stability under continuous operation. Especially, OPVs suffer from a rapid decrease in PCE during initial device operation, which is known as the “burn-in loss”. It is considered that the origin of the burn-in loss is mainly related with the instability of the BHJ morphology and/or interface rather than the photooxidation of the photoactive layer. We find that the photoactive layer prepared by a sequential solution deposition is more stable than that prepared by blend solution deposition. We also find that the burn-in loss is closely related with stability of photoactive layer / electron transporting layer interface.