We introduce a method based on gold-assisted exfoliation for deterministic, large-area exfoliation of few-layer transition metal dichalcogenides with precise control of layer number N. This technique uses a hybrid gold tape to create (N - 1)-layer terraces on a bulk crystal. The terraces, along with a continuous monolayer below, are subsequently cleaved using uniform gold tape to yield N-layer regions. The high electronic quality of the material is confirmed through the fabrication of field-effect transistors (FETs) from exfoliated monolayer, bilayer, and trilayer MoS2, which exhibit carrier mobilities of up to 160 cm2 V-1 s-1. This exfoliation technique can be combined with stacking and atomic layer etching to create a versatile toolkit to achieve more complex structures, including moiré heterostructures. This work demonstrates a robust and scalable route to engineering high-quality, few-layer 2D materials for electronic and quantum devices.
Yoon et al. (Mon,) studied this question.