Interconnecting layers for tandem organic solar cells

Abstract Tandem structure provides a practical way to realize high efficiency organic solar cells (OSCs). It overcomes several bottlenecks in single junction OSCs such as thermalization loss, transmission loss and inefficient light absorption. In tandem OSCs, the interconnecting layer (ICL) electrically connects two subcells and it plays a critical role in determining the device performance and reproducibility. In this review paper, we first give a brief introduction on the working mechanism and the requirements for ICLs. We then compare three classes of ICLs based on their optical, mechanical and chemical properties. Finally, the possible paths forward for tandem OSCs are discussed.