Recent Advancements on Materials Synthesis and Applications of Bismuth Oxyselenide

Two‐dimensional materials experience rapid development in the field of photoelectronic devices due to their unique electronic structures and excellent optoelectronic properties. As an emerging 2D material, Bi 2 O 2 Se features distinctive interlayer interactions with weak electrostatic forces, generating excellent air stability, tunable bandgap, and ultra‐high carrier mobility, which render it a promising candidate for advanced electronic and optoelectronic devices, including smart wearable equipment, flexible electronic devices, visual imaging, encrypted communication, and artificial synapses. This review represents a comprehensive overview of recent advances in 2D Bi 2 O 2 Se materials, covering aspects such as the crystal and band structures, physical properties, substrate selection, and preparation methods as well as practical applications, with a focus on their research advancement in broadband photodetection, flexible photodetection, optical imaging, optical communication, artificial synapses, and so on. Finally, current challenges and future perspectives are discussed to guide further exploration and application of Bi 2 O 2 Se in next‐generation multifunctional optoelectronic technologies.