Flexible electronics and optoelectronics of 2D van der Waals materials

Flexible electronics and optoelectronics exhibit inevitable trends in next-generation intelligent industries, including healthcare and wellness, electronic skins, the automotive industry, and foldable or rollable displays. Traditional bulk-material-based flexible devices considerably rely on lattice-matched crystal structures and are usually plagued by unavoidable chemical disorders at the interface. Two-dimensional van der Waals materials (2D VdWMs) have exceptional multifunctional properties, including large specific area, dangling-bond-free interface, plane-to-plane van der Waals interactions, and excellent mechanical, electrical, and optical properties. Thus, 2D VdWMs have considerable application potential in functional intelligent flexible devices. To utilize the unique properties of 2D VdWMs and their van der Waals heterostructures, new designs and configurations of electronics and optoelectronics have emerged. However, these new designs and configurations do not consider lattice mismatch and process incompatibility issues. In this review, we summarized the recently reported 2D VdWM-based flexible electronic and optoelectronic devices with various functions thoroughly. Moreover, we identified the challenges and opportunities for further applications of 2D VdWM-based flexible electronics and optoelectronics.