Modifying the buried interface with azodicarbonamide for high-efficiency MA-free perovskite solar cells

Although perovskite solar cells have achieved huge progress, there is still unprecedented room for improvement since there exist non-radiative recombinations at the interface. Herein, we employed azodicarbonamide to modify the buried interface for promoting power conversion efficiency and stability. Azodicarbonamide can not only reduce the defects at the buried interface but also can improve the quality of the perovskite film due to the possible chemical interaction with perovskite. In addition, a matched interfacial energy level is conducive to the transport of charge carriers. Finally, the perovskite solar cells achieved a power conversion efficiency of 22.52% and attractive stability. This work demonstrates a simple interface modification strategy for the highly-performed perovskite solar cells, which is beneficial to their commercialization process.