Progress Report on Property, Preparation, and Application of Bi2O2Se

Abstract The study of 2D materials has been a significant and fascinating area, at least since the discovery of graphene. As one of the layered bismuth oxychalcogenides, bismuth oxyselenide (Bi 2 O 2 Se) has drawn a lot of attention recently. The study of Bi 2 O 2 Se was mainly focused on its thermoelectric performance until its ultrathin 2D structure came to the fore. New physical properties of Bi 2 O 2 Se were discovered along with the successful synthesis of 2D Bi 2 O 2 Se structures. Few‐layer Bi 2 O 2 Se exhibits ultrahigh mobility, outstanding stability, tunable bandgaps, and excellent mechanical properties, showing remarkable performance in electronics and optoelectronics. In this report, an overview of recent advances in Bi 2 O 2 Se research is provided, including structure/property modifications, synthetic methods, and practical applications. Theoretical and experimental results on bulk/few‐layer Bi 2 O 2 Se are both discussed in this report. Finally, the challenges and outlook for Bi 2 O 2 Se are evaluated based on current progress.