Gold‐Assisted Exfoliation of Large‐Area Monolayer Transition Metal Dichalcogenides: From Interface Properties to Device Applications

Semiconductor transition metal dichalcogenides (TMDs), such as MoS2, are currently regarded as key-enabling materials for sub-1 nm channel transistors, beyond-complementary metal–oxide–semiconductor electronic and optoelectronic devices and sensors. Owing to this wide application potential, several bottom-up and top-down synthesis approaches for these materials have been explored so far. Despite the huge progresses in scalable deposition methods (such as chemical vapor deposition, metal–organic chemical vapor deposition), exfoliated layers from bulk crystals still represent the benchmark for record electronic properties of TMDs. Among exfoliation approaches, metal-assisted mechanical exfoliation emerges as the most effective method to separate large-area (mm2 to cm2) single-crystalline monolayer membranes of TMDs (and many other 2D materials) from the parent bulk crystals. This paper reviews the state-of-the-art in this field, from current understanding of MoS2 exfoliation mechanisms on Au (considered as a model system), to the main device applications of as-exfoliated and transferred large-area MoS2 membranes (including Au/MoS2/Au memristors, MoS2 photodetectors, and field-effect transistors). Perspectives of this method in the realization of arrays of 2D heterojunction devices, including Moirè superlattice devices, and open challenges for its widespread application are finally discussed.