Defect Creation Dynamics of Graphene through Scanning Probe Lithography
Wei Huan, Chiang1*, Hung Chieh, Tsai1, Min Chiang, Chuang1, Hung Wei, Shiu2, Wei Yen, Woon1, Chia Hao, Chen2
1Condensed Matter Lab, National Central University, Toayuan, Taiwan
2National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan
* presenting author:Wei Huan Chiang,
Graphene, as a unique two dimensional honeycomb lattice consisting sp2 bonded carbon atoms, has the unique electronic properties and high potential to be electronic applications. However, it's very difficult to control the electrons moving through graphene because graphene has no band gap, which means that electrons don't need to cross any energy barrier in order to conduct electricity. The absence of the energy gap limits its application for switching devices. One of the way to open band gap can be controlled by the majority of oxygen-containing functional groups. With X-ray photoelectron spectroscopy, we can determine the chemical composition of defect. It can compare to the structure and surface properties by the measurement of Raman spectroscopy and atomic force microscopy.

Here, we introduce the defect created by scanning probe lithography (SPL) with different external electric field on CVD grown graphene. The presence of defect determine the electrical performance, such as electron mobility. On the other hand, the defect can also change the chemical and electrical properties in a good way. We investigate using atomic force microscopy, micro-Raman spectroscopy (μ-RS) and micro-X-ray photoelectron spectroscopy (μ-XPS). μ-RS determine the initial defect density for the graphene by the effective crystallized domain size (La=ID/IG). μ-XPS revealed the degree of oxidation and composition of local defect. The defect creation dynamics of graphene through SPL is reported.

Keywords: graphene, scanning probe lithography, defect