Efficient transfer of large-area graphene films onto rigid substrates by hot pressing.
Graphene films grown on metal substrates by chemical vapor deposition (CVD) method have to be safely transferred onto desired substrates for further applications. Recently, a roll-to-roll (R2R) method has been developed for large-area transfer, which is particularly efficient for flexible target substrates. However, in the case of rigid substrates such as glass or wafers, the roll-based method is found to induce considerable mechanical damages on graphene films during the transfer process, resulting in the degradation of electrical property. Here we introduce an improved dry transfer technique based on a hot-pressing method that can minimize damage on graphene by neutralizing mechanical stress. Thus, we enhanced the transfer efficiency of the large-area graphene films on a substrate with arbitrary thickness and rigidity, evidenced by scanning electron microscope (SEM) and atomic force microscope (AFM) images, Raman spectra, and various electrical characterizations. We also performed a theoretical multiscale simulation from continuum to atomic level to compare the mechanical stresses caused by the R2R and the hot-pressing methods, which also supports our conclusion. Consequently, we believe that the proposed hot-pressing method will be immediately useful for display and solar cell applications that currently require rigid and large substrates.
SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon, 440-746, Korea.
Junmo
J
Kang
Soonhwi
S
Hwang
Jae Hwan
JH
Kim
Min Hyeok
MH
Kim
Jaechul
J
Ryu
Sang Jae
SJ
Seo
Byung Hee
BH
Hong
Moon Ki
MK
Kim
Jae-Boong
JB
Choi
D004553:Electric Conductivity; D006108:Graphite / Q000737:chemistry*; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D054802:Molecular Imprinting / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011312:Pressure; D013499:Surface Properties
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D006108:Graphite