Solution-processed cathode interfacial layer materials for high-efficiency polymer solar cells

Polymer solar cells (PSCs) are a new type of renewable energy source currently being extensively investigated due to perceived advantages; such as being lightweight, low-cost and because of the unlimited materials resource. The power conversion efficiency of state-of-the-art PSCs has increased dramatically in the past few years, obtained mainly through the development of new electron donor polymers, acceptors, and novel device structures through the use of various electrode interfacial materials. In this short review, recent progress in solution-processed cathode interfacial layers that could significantly improve device performances is summarized and highlighted.