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URN etd-0810111-160522 Statistics This thesis had been viewed 3267 times. Download 4662 times. Author Yung-en Chu Author's Email Address No Public. Department Electro-Optical Engineering Year 2010 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 100 Title Field emission from free-standing graphene edges and applied in scanning tunneling microscopy Keyword Scanning tunneling microscopy Graphene Field emission Field emission Graphene Scanning tunneling microscopy Abstract Graphene is a two dimension sheet of carbon crystal, it has shown excellent electrical conductivity and good mechanical properties, which reveal its potential to use for field emission electron source. We report the fabrication and field emission properties of graphene edges from a stable suspension graphene cantilever which prepared by rapid quenching of highly oriented pyrolytic graphite (HOPG) in an aqueous solution of NH4HCO3. Field emission properties were investigated using graphene assembled on a tungsten tip for instrumentation as field emission microscopy (FEM).
Our field emission results show that stable field emission currents from graphene edges can be obtained after activated by using high electric field and careful conditioning process within several continuous testing cycles. During conditioning process, the turn on voltage settled. The characteristics of field emission from graphene edges show its turn on electric field of 3 V/μm at current of 5.96 μA with stability of 4.6％. Furthermore, we also obtained the resolved FEM patterns from single-layer and 3-layer graphene edges. There’s only optimal limited atoms will emits electrons from a graphene edge. Due to these property, we used our prototype free-standing single-layer graphene probe to applied in scanning tunneling microscopy(STM). Comparing with classic STM tip, the graphene probe have fairly good resolution in nano-meter scale.
Advisor Committee Dr. Jeff Tsung-Hui Tsai - advisor
Files Date of Defense 2011-07-25 Date of Submission 2011-08-11