Large-scale growth, fluorination, clean transfer, and layering of graphene and related nanomaterials

graphene;hexagonal boron nitride;transfer;synthesis;functionalization;fluorine;scanning tunneling microscopy;Raman spectroscopy;biomolecules;denaturation;layering

Wood, Joshua

关键词: graphene;    hexagonal boron nitride;    transfer;    synthesis;    functionalization;    fluorine;    scanning tunneling microscopy;    Raman spectroscopy;    biomolecules;    denaturation;    layering;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/46670/Joshua_Wood.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This dissertation improves the synthesis, functionalization (i.e., fluorination), and transfer of graphene and hexagonal boron nitride (h-BN). Further, this document explores new avenues in the large-area, heterogeneous layering of graphene, h-BN, and related nanomaterials like nanoscale water and biomolecules.It is determined that monolayer, high-quality graphene growth by chemical vapor deposition (CVD) on Cu depends on the substrate’s crystallography, with few-defect, monolayer graphene growing on Cu(111). Functionalizing CVD graphene with XeF2 produces fluorinated graphene (FG) with C4F and CF stoichiometries. FG films seed high-κ HfO2 films better than pristine graphene. An atomically clean nanomaterial transfer method using poly(bisphenol A carbonate) (PC) is developed and benchmarked against alternative transfer scaffolds. A transferred CVD graphene overlayer encapsulates one to three nanoscale water layers on mica. The graphene shrink wrapped water is highly viscous and robust, withstanding ultra-high vacuum and high-temperature treatments.The PC transfer process is then used to shrink wrap heterogeneous combinations of graphene, h-BN, FG, water, CNTs, and biomolecules like tobacco mosaic viruses, proteins, and DNA. Biomolecules under graphene shrink wrap undergo pressure denaturation, affecting vicinal hydration. The water crystallizes at MBD-DNA complexes and spinodally dewets at pressure-denatured NA proteins on mica. Finally, the CVD growth of h-BN progresses from planar, large-grain films to amorphous, polymeric films as surface catalysis is suppressed and the growth pressure is increased. Also, the CVD h-BN films are thicker and more defective on high-index Cu facets versus low-index Cu(100).