Controlled Growth of Vertical‐Standing Bandgap‐Tunable Perovskite Nanoplates for Multicolor Photodetectors

Multicolor detection and image transmission technologies across multiple wavelengths exhibit great application prospects in the fields of autonomous driving, security monitoring, biological imaging, and related fields. However, despite significant advances in perovskite‐based multicolor detection, achieving high performance and stability in complex perovskite systems remains a considerable challenge. In this work, the first controlled synthesis of vertical‐standing bandgap‐tunable CsPb(Br 1‐ x I x ) 3 ( x = 0 to 1) triangular nanoplates is reported via a CVD method combined with elemental substitution. The synthesized CsPb(Br 1‐ x I x ) 3 triangular nanoplates exhibit lateral dimensions up to several tens of micrometers and tunable photoluminescence ranging from green (530 nm, 2.34 eV) to red (709 nm, 1.75 eV). Furthermore, photodetectors based on the CsPb(Br 1‐ x I x ) 3 perovskite demonstrate high‐performance detection and image transmission at specific wavelengths (520, 590, and 660 nm). More importantly, by integrating customized perovskite devices with a neural network algorithm, a traffic light recognition system is developed with a recognition accuracy of 92.78%. The vertical‐standing, bandgap‐tunable perovskite materials represent a promising material platform for integrated photonics, with broad potential in multicolor detection, display technologies, and intelligent sensing applications.