All-Dry Transfer of Graphene Film by van der Waals Interactions

Abstract

We report a method that uses van der Waals interactions to transfer continuous, high-quality graphene films from Ge(110) to a different substrate held by hexagonal boron nitride carriers in a clean, dry environment. The transferred films are uniform and continuous with low defect density and few charge puddles. The transfer is effective because of the weak interfacial adhesion energy between graphene and Ge. Based on the minimum strain energy required for the isolation of film, the upper limit of the interfacial adhesion energy is estimated to be 23 meV per carbon atom, which makes graphene/Ge(110) the first as-grown graphene film that has a substrate adhesion energy lower than that of typical van der Waals interactions between layered materials. Our results suggest that graphene on Ge can serve as an ideal material platform to be integrated with other material systems by a clean assembly process.

Pattern Pick and Place Method for Twisted Bi- and Multi-Layer Graphene

“…After the gold pattern was fabricated on the as-grown graphene, the thermal annealing in an H 2 atmosphere resulted in hydrogen intercalation between the graphene and the Ge substrate [26,27]. As a result, adhesion between the graphene and the underlying Ge substrates became extremely weak [24,28]. The PPC/PDMS stamp had a weak adhesion with graphene but a strong adhesion with gold, so the gold pattern and the underlying graphene could be selectively lifted (picked up) from the Ge substrate.…”

Wafer‐scale vertical van der Waals heterostructures

“…99 After subsequently growing h-BN on the top of graphene, a centimeter-size h-BN/Gr vdWH was fabricated, which could be transferred to an arbitrary substrate using a TRT owing to the weak bondage between Ge and graphene. 99 In addition, vdWHs based on h-BN can be prepared in a similar fashion. Monolayer MoS 2 was synthesized through LPCVD on the top of high-temperaturegrown h-BN, yielding a vertical-stacked MoS 2 /h-BN heterostructure at centimeter scale.…”

“…This was realized by using the liquid Cu as the growth substrate for graphene in the first deposition procedure 98 . Other than growth on metal substrates, graphene was also synthesized on a germanium (Ge) substrate by CVD 99 . After subsequently growing h‐BN on the top of graphene, a centimeter‐size h‐BN/Gr vdWH was fabricated, which could be transferred to an arbitrary substrate using a TRT owing to the weak bondage between Ge and graphene 99 .…”

Photoelectric Characteristics of Reduced Graphene Oxide/Silver Nanoparticles Multilayer Films via Spin-Coating and Self-Assembly

“…Contrast to graphene oxide, the interlayer spacing of graphene becomes smaller, which indicates that most of the oxygen-containing functional groups are removed by hydrogen during the heat treatment, the van der Waals interaction between layers is enhanced. 26) At the same time, the XRD peaks of the nanoparticles are not observed in the diffraction pattern because fewer nanoparticles in the film have weaker diffraction signals. Table 1 Zeta-potential of graphene oxide and silver nanoparticles.…”