High pressure studies of 2D materials and heterostructures: A review

2D materials and their heterostructures (HSs) hold great promises for a number of future applications, owing to their unique layered structure and excellent properties, both of which can be tuned by a number of techniques. Among various tuning methods, pressure engineering using diamond anvil cell (DAC) is a highly effective in-situ and reversible technique, which can efficiently modulate the structure and physical properties of 2D materials. In this review, we survey recent researches based on pressure engineering in 2D materials and HSs, focusing on the advantages and challenges in experimental study using DAC, as well as the combination of high-pressure capability with other experimental techniques for in-situ characterization of structural, optical, and electrical properties, all under high pressure.