Thermal-Driven Phase Separation of Double-Cable Polymers Enables Efficient Single-Component Organic Solar Cells

Summary Conventional organic solar cells (OSCs) need two components that function as donor and acceptor, respectively. Although there has been wishful thinking about constructing OSCs based on a single component, it is generally believed to be highly challenging to achieve efficient single-component OSCs (SCOSCs). In this work, we design a new double-cable conjugated polymer containing a strongly crystalline backbone as donor and aromatic side units as acceptor. With a high annealing temperature (230°C), both the backbones and perylene bisimide side units could self-organize into ordered nanostructures. This enables efficient charge transport and low charge recombination, resulting in a record efficiency of 6.3% in SCOSCs. The cells also exhibit excellent stability, with >90% efficiency retention over 300 h of continuous one-sun illumination. These results suggest that the concept of SCOSCs is highly promising, especially to overcome the limitations of conventional OSCs toward industrial application.