Interlayer engineering for efficient organic solar cells.

Donor-acceptor (D/A) combinations consisting of polymer (or small molecule) donors and fullerene acceptors (FAs) have dominated the market for organic solar cells (OSCs) for over two decades. The power conversion efficiencies (PCEs) of fullerene acceptor-based organic solar cells have exceeded 13 percent in recent years. The discovery of non-fullerene acceptors (NFAs), which provide synthetic flexibility, a high absorption capacity, and superior thermal durability, has resulted in power conversion efficiencies (PCEs) in single junction devices that approach 18%. Moreover, the installation of interlayers between the D/A (active layer) and electrodes is essential for charge collection and transfer, increases the device's performance, and makes it more stable. In this article, the engineering techniques for interlayers are addressed based on the work mechanisms they do in NFAs-based OSCs. These techniques enhance the efficiency of power conversion and OSC stability. The paper concluded with a summary of the key issues confronting interlayer engineering as well as the future paths for the development of OSCs. [ABSTRACT FROM AUTHOR]