Flexible organic solar cells: Materials, large-area fabrication techniques and potential applications

Organic solar cells (OSCs) that converted sunlight into electricity have obtained numerous progress in the past two decades. With the efforts of developing new conjugated materials, the power conversion efficiencies (PCEs) of OSCs have realized over 18%, which are comparable with other types of solar cells. These great achievements enable OSCs to arrive at the key period toward industrial application. Flexibility is the main characteristic of OSCs, which endows OSCs to be applied into special fields. In this review, we will provide an overview about the research progress of flexible OSCs (F-OSCs), from the aspect of materials (including flexible electrodes, interfacial layers and photoactive layers), large-area fabrication techniques and potential applications. These advancements enable F-OSCs to achieve PCEs over 15% with high stability, and we will also discuss the problems in F-OSCs. We hope that with this review, more studies from the academia and industrial community will be involved into F-OSCs, especially focusing on new materials toward application in the future.