Interface engineering for high performance polymer and perovskite solar cells

Interface engineering is a critical strategy for improving the performance of both polymer and organometal trihalide perovskite (e.g., CH
3
NH
3
PbI
3
) solar cells. A good interfacial material should fulfill several requirements including 1) good charge selectivity to improve the charge collection efficiency at the corresponding electrodes, 2) matched energy levels with the conduction band and valence band of the light harvesting film to maximize the photovoltage of the solar cells, 3) high conductivity to minimize the interfacial resistance loss and forming Ohmic contact with the electrodes [1]. In the first part of my talk I will discuss several strategies to design new conjugated polymer-based interfacial materials with desired electrical conductivity, energy levels and processibility to improve the charge collection efficiency of polymer solar cells [2]. The application of these interfacial materials as interconnection layer for highly efficient tandem polymer solar cells will also be discussed [3]. In the second part of my talk, I will discuss how we can apply the knowledge we learned from the interface engineering of polymer solar cells to design new class of electron transport layer [4] and hole transport layer materials [5] to improve the performance of perovskite solar cells.