Applied Surface Science, Vol.493, 81-86, 2019
Wax-assisted crack-free transfer of monolayer CVD graphene: Extending from standalone to supported copper substrates
The transfer of CVD graphene grown on catalytic copper with an additional supporting substrate is different from that grown on the standalone copper foils, and the flexible polymer-based transfer supports are not quite suitable. For this purpose, we invented a wax-assisted crack-free graphene transfer method by taking advantage of the low polarity, high rigidity, and molecular-mixing nature of wax. Unlike other small-molecule transfer supports, the amorphous wax effectively mitigates the interfacial thermal stress caused by phase transition, enabling a clean and integral graphene transfer. Microscopic and spectroscopic characterizations reveal less doping defects of the wax-transferred graphene than its PMMA-transferred counterpart, demonstrating great electric properties with high electron and hole mobilities. Consequently, this new transfer method provides a universal solution for CVD graphene grown on various substrates, and paves the way for further extending their applications.