Large-area transfer of two-dimensional materials free of cracks, contamination and wrinkles via controllable conformal contact

Abstract

The availability of graphene and other two-dimensional (2D) materials on a wide range of substrates forms the basis for large-area applications, such as graphene integration with silicon-based technologies, which requires graphene on silicon with outperforming carrier mobilities. However, 2D materials were only produced on limited archetypal substrates by chemical vapor deposition approaches. Reliable after-growth transfer techniques, that do not produce cracks, contamination, and wrinkles, are critical for layering 2D materials onto arbitrary substrates. Here we show that, by incorporating oxhydryl groups-containing volatile molecules, the supporting films can be deformed under heat to achieve a controllable conformal contact, enabling the large-area transfer of 2D films without cracks, contamination, and wrinkles. The resulting conformity with enhanced adhesion facilitates the direct delamination of supporting films from graphene, providing ultraclean surfaces and carrier mobilities up to 1,420,000 cm2 V−1 s−1 at 4 K.

Controlled Growth of Bilayer Graphene on Space-Confined Cu Substrates

“…With the increase of the layer thickness of graphene, the value of I 2D /I G was decreased from 2 to 0.4, and a blue-shifted 2D band with an increased FWHM(2D) from 28 to 60 cm −1 was also observed. Electrical transport measurements were conducted on a dual-gate Hall bar device, in which bilayer graphene was transferred onto the 300-nm-thick SiO 2 /Si substrate with a semi-dry transfer method, 23 and a film of 15-nm-thick HfO 2 was utilized as the top gate dielectric. The resistance as a function of top gate voltage at room temperature is demonstrated in Figure 3a, and the carrier mobilities are obtained as 2183 cm 2 V −1 s −1 for holes and 1099 cm 2 V −1 s −1 for electrons, respectively (see more details in Supporting Notes and Figure S7).…”

“…Specifically, the suspended graphene membrane on the commercial TEM grid was fabricated via a polymer-free transfer method . Thermal release tape was used for the semi-dry transfer of bilayer graphene to fabricate a Hall bar device . Besides, a poly­(methyl methacrylate) (PMMA)-assisted method was utilized to transfer graphene onto SiO 2 /Si and quartz substrates for Raman and optical transmittance characterization, respectively …”

“…22 Thermal release tape was used for the semidry transfer of bilayer graphene to fabricate a Hall bar device. 23 Besides, a poly(methyl methacrylate) (PMMA)-assisted method was utilized to transfer graphene onto SiO 2 /Si and quartz substrates for Raman and optical transmittance characterization, respectively. 24 Characterization.…”

Progress in the Development of Active-Matrix Quantum-Dot Light-Emitting Diodes Driven by Non-Si Thin-Film Transistors

“…On the other hand, exfoliation-based deposition and fine-patterning of the TMDC monolayer are the major obstacles to their application in large-area AM displays. Although technologies for high-resolution and large-scale fabrication have consistently progressed [ 49 , 50 , 51 ], they need to be developed more to satisfy customer expectations for large-sized displays.…”

Determination of the preferred epitaxy for III-nitride semiconductors on wet-transferred graphene

“…Wafer-scale single-crystal graphene can be mass-produced on several kinds of substrates, such as Cu(111) (1,2), Cu-Ni alloy (3), and Cu(111)/Al 2 O 3 (0001) (4). The graphene can then be transferred to a target substrate surface (5)(6)(7), providing an attractive platform for fabricating III-nitride semiconductor devices. On such a platform, graphene can be used to alter the epitaxial relationship between the III-nitride semiconductor and the substrate, leading to single-crystal films on arbitrary substrates such as single-crystal Al 2 O 3 (8,9) and polycrystalline diamond (10).…”