Two‐dimensionalization of 3D perovskites for passive narrowband Photodetection

Abstract In the rapidly advancing field of information technology, passive sensors with the exemption of external power input can serve as intelligent instruments for end‐node data acquisition. 3D perovskites have been recognized as a superior optoelectronic material but suffering from notorious instability due to their “soft lattice” nature. Replacing by their 2D counterparts in these photo‐sensing applications can boost the reliability level. However, traditional fabrication for 2D perovskite relay on wet chemistry methods, exhibiting complication, and inefficiency in making high‐quality films for device integration. This study unveils a new solid–solid conversion routing toward a direct transformation from 3D orientated films into 2D highly crystalline configuration, based on a spontaneous lattice regulation mechanism through an amine steam treatment. The resultant 2D film exhibits greater orientational micromorphology and a distinct monochromatic narrowband light sensing behavior after integration into a self‐powered photodetector. This method on perovskite conversion bears the promise of advanced future‐manufacturing for high‐performance photonic sensing. image