Versatile third components in organic ternary solar cells

The record of power conversion efficiency (PCE) of organic solar cells (OSCs) is updating every day, and the value has exceeded 19% already, but it still lags behind those of commercialized inorganic solar cells. The addition of a third component not only can reduce energy loss for achieving a higher open circuit voltage (VOC), but also can enlarge the light harvesting range as well as optimize morphology for getting a higher short circuit current (JSC) and fill factor (FF). For further promoting the development of organic photovoltaic technology, this article first presents general principles of organic ternary solar cells (OTSCs), and then summarizes the recent developments of OTSCs in terms of the roles of third component. In the end, the challenges and perspectives for OTSCs are discussed. This review may provide guidance for preparing highly efficient organic ternary solar cells.