Review and comparison of layer transfer methods for two-dimensional materials for emerging applications

Abstract

Two-dimensional (2D) materials offer immense potential for scientific breakthroughs and technological innovations.

Perspectives of 2D Materials for Optoelectronic Integration

“…More specifically, top‐down methods mainly include micromechanical exfoliation and liquid phase exfoliation methods, [ 15,33–42 ] while bottom‐up methods generally include chemical vapor deposition (CVD) and hydrothermal/solvothermal methods. [ 43–53 ]…”

“…More specifically, top-down methods mainly include micromechanical exfoliation and liquid phase exfoliation methods, [15,[33][34][35][36][37][38][39][40][41][42] while bottom-up methods generally include chemical vapor deposition (CVD) and hydrothermal/solvothermal methods. [43][44][45][46][47][48][49][50][51][52][53] In earlier studies of 2D material, the preparation of 2D nanosheets for fundamental property investigation and functional device fabrication is highly relied on the micromechanical exfoliation. [15] Because the in-plane chemical bonds in 2D materials are much stronger than the interlayer bonds, it is possible to exfoliating their bulk materials down to monolayer limits.…”

“…[50] Thereby, the follow-up steps that are used to transfer the 2D materials to arbitrary substrates is necessary. [51,52] Whereas, the additional transfer steps are timeconsuming and may introduce residues or defects which will deteriorate the material properties. On all accounts, synthesis of high-quality 2D material is essential for their optoelectronic applications, which needs continuous efforts in the near future.…”

Large-Area Transfer of 2D TMDCs Assisted by a Water-Soluble Layer for Potential Device Applications

“… 15 Significant efforts have been made to transfer 2D material films without degrading the film quality, which is critical for the success of 2D materials. 23 − 28 In early studies, hazardous chemical etchants such as hydrofluoric acid (HF), hydrochloric acid (HCl), and nitric acid (HNO 3 ) were used to transfer 2D materials, which are environmentally unfriendly and degrade the film quality. 24 , 29 Strong bases such as KOH and NaOH have also been used to transfer the 2D material film, which are more attractive than hazardous chemical etchants.…”

Co-assembled Perylene/GO Photosensitive Heterobilayer for Efficient Neuromorphics

“…Several inorganic bilayer heterostructures, including WSe 2 -MoS 2 15 , WSe 2 -SnS 2 16 , and GaTe-MoS 2 17 , have been successfully constructed. However, there are still a few imperfections in the resulting materials, such as grain boundaries with weak homogeneity 18 , unscalable exfoliation with ine cient transfer 19 , and complicated processes with high expense. Furthermore, the relatively high mobility of inorganic layered crystals (100 cm 2 V −1 s −1 ) normally accompanies a relatively high dark current and operating current simultaneously, thus making it hard to enhance the speci c detectivity and reduce the power dissipation in man-made synapses, all of which limit the practicality of monolithically large-scale manufacturing and competitive applications.…”