Buried Interface‐The Key Issues for High Performance Inverted Perovskite Solar Cells

Abstract Interface engineering is known for effectively improving interfacial contact and passivating defects to enhance device performance of inverted perovskite solar cells (PSCs). Currently, most of works focus on surface passivation, while the buried interface is equally important. The film quality of perovskite layer greatly relies on the buried interface, leaving a pronounced impact on overall device performance. In addition, resolving defects and energy level mismatch at buried interface remains challenging. Optimizing the buried interface becomes a promising approach for high‐efficiency inverted PSCs. This review summarizes recent advances in buried interface engineering and emphasize the importance of corresponding characterization techniques. The various functions of buried interface engineering are carefully discussed, including crystallization modulation, defect passivation, energy level alignment, chemical reaction inhibition, chemical bridge, dipole cancellation and novel buried interfacial techniques. Finally, current challenges and prospects are put forward that should be addressed to further improve device performance of inverted PSCs.