Engineering Amorphous-crystallized Interface of ZrN x Barriers for Stable Perovskite Solar Cells.

It is challenging to achieve long-term stability of perovskite solar cells due to the corrosion and diffusion of metal electrodes. Integration of compact barriers into devices has been recognized as an effective strategy to protect the perovskite absorber and electrode. However, the difficulty is to construct a thin layer of a few nanometers that can delay ion migration and impede chemical reactions simultaneously, in which delicate microstructure design of a stable material plays an important role. Herein, ZrN x barrier films with high amorphization were introduced in perovskite solar cells. To quantify the amorphous-crystalline (a-c) density, we employed pattern recognition techniques for the first time. We found the decreasing (a-c) interface in an amorphous film lead to dense atom arrangement and uniform distribution of chemical potential, which retards the interdiffusion at the interface between ions and metal atoms and protect the electrodes from corrosion. The resultant solar cells exhibited an improved operational stability, which retained 88% of initial efficiency after continuous maximum power point tracking under 1-Sun illumination at room temperature (25 ˚C) for 1500 hours. This article is protected by copyright. All rights reserved.