Recent Advances in the Growth Strategies, Multifunctional Properties, and Emerging Applications of Two‐Dimensional Non‐van der Waals Bismuth Oxychalcogenides and Prospective Heterostructures

Abstract

With the advent of two‐dimensional (2D) van der Waals (vdW) materials, many non‐van der Waals (nvdW) materials have been synthesized and are being exploited for novel applications. Bismuth oxychalcogenides (Bi2O2X; X is S, Se, Te), a nvdW series with moderate band gap semiconductors, possess high carrier mobility and air stability. The layers in Bi2O2X stay with a formal bond, giving rise to distinct structural, optical, thermal, and electronic properties different from conventional vdW materials. Herein, these properties, their synthesis, and transfer methods of 2D Bi2O2X are examined. The photodetector application of Bi2O2X and their heterostructure (HS) is surveyed with special attention to Bi2O2Se. Beyond the photodetector, the other emerging application fields, such as gas‐bio sensors, optoelectronic imaging, integrated memory, solar cells, and photothermal technology of Bi2O2X are looked over. Based on the ongoing research and challenges, the strategies for future innovations are presented from basics to miniaturized applications. In view of the band offsets of vdW and nvdW semiconductors, the type of HS of a series of 94 vdW‐nvdW sets is proposed. This review will guide future studies on Bi2O2X and their HS to meet the increasing demands in multifunctional applications from the laboratory to the industrial scale.