Recent Progress of Transfer Methods of Two-Dimensional Atomic Crystals and High-Quality Electronic Devices

Two-dimensional atomic crystals (2DACs) are the layered materials that can be exfoliated into the thickness of one unit cell, and attract extensive attention in current condensed matter physics. The atoms contained in a 2DAC are completely exposed, thus rendering them extremely sensitive to the external environment. Therefore, the exfoliation, transfer, rotation, stacking, encapsulation and device fabrication processes are particularly important for the electronic device quality and electrical transport properties of 2DACs. We review the recent progress of the transfer methods for 2DACs, especially the milestones in the improving of the transport properties of these two-dimensional electron gases (2DEGs). For electronic devices based on 2DACs, the quality of the devices is evaluated in terms of the disorder of 2DEG, contact resistance, carrier mobility, and observed quantum Hall states, and their corresponding transfer technology, device structure and fabrication processes are also discussed in detail.