Designed Growth of Large-Size 2D Single Crystals

In the "post-Moore's Law" era, new materials are highly expected to bring next revolutionary technologies in electronics and optoelectronics, wherein 2D materials are considered as very promising candidates beyond bulk materials due to their superiorities of atomic thickness, excellent properties, full components, and the compatibility with the processing technologies of traditional complementary metal-oxide semiconductors, enabling great potential in fabrication of logic, storage, optoelectronic, and photonic 2D devices with better performances than state-of-the-art ones. Toward the massive applications of highly integrated 2D devices, large-size 2D single crystals are a prerequisite for the ultimate quality of materials and extreme uniformity of properties. However, at present, it is still very challenging to grow all 2D single crystals into the wafer scale. Therefore, a systematic understanding for controlled growth of various 2D single crystals needs to be further established. Here, four key aspects are reviewed, i.e., nucleation control, growth promotion, surface engineering, and phase control, which are expected to be controllable at different periods during the growth. In addition, the perspectives on designed growth and potential applications are discussed for showing the bright future of these advanced material systems of 2D single crystals.