The roles of wetting liquid in the transfer process of single layer graphene onto arbitrary substrates.
Wet transfer is crucial for most device structures of the proposed applications employing single layer graphene in order to take advantage of the unique physical, chemical, bio-chemical and electrical properties of the graphene. However, transfer methodologies that can be used to obtain continuous film without voids, wrinkles and cracks are limited although film perfectness critically depends on the relative surface tension of wetting liquids on the substrate. We report the importance of wetting liquid in the transfer process with a systematic study on the parameters governing film integrity in single layer graphene grown via chemical vapor deposition. Two different suspension liquids (in terms of polar character) are tested for adequacy of transfer onto SiO2 and hexamethyldisiloxane (HMDS). We found that the relative surface tension of the wetting liquid on the surfaces of the substrate is related to transfer quality. In addition, dimethyl sulfoxide (DMSO) is introduced as a good suspension liquid to HMDS, a mechanically flexible substrate.
Department of Electronic Engineering, Hanyang University, Seoul 133-791 South Korea.
Ju Hun
JH
Kim
Junghwa
J
Yi
Hyeong Ki
HK
Jin
Un Jeong
UJ
Kim
Wanjun
W
Park
D000327:Adsorption; D003460:Crystallization / Q000379:methods; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties; D017155:Wettability; D014906:Wetting Agents / Q000737:chemistry*
D046911:Macromolecular Substances; D014906:Wetting Agents; D006108:Graphite; D004121:Dimethyl Sulfoxide