Multiscale Simulations of Graphene Defect Properties and Growth Mechanisms

Graphene, a two-dimensional (2D) material consisting of [IMAGE png]-hybridized carbon atoms, has outstanding electronic, thermal, and mechanical properties, suggesting that it might play an important role in future electronic and nanoelectromechanical devices. The methods for fabricating graphene films include mechanical exfoliation, thermal sublimation of silicon carbide, reduction of graphene oxide, and chemical vapor deposition (CVD) growth on polycrystalline Cu or Ni substrates using methane as the carbon source and Cu or Ni as catalysts. Among these methods, CVD growth is probably the most promising because it allows the possibilities of fabricating low-cost, high-quality, and large-area graphene films. Nevertheless, impurities, dislocations, and grain boundaries (GBs) are very likely to be introduced, and these defects have significant effects on the mechanical, thermal, and electronic properties of graphene films. Thus, understanding the structures and dynamics of defect and their effects on the material properties of graphene will be necessary for the reliable fabrication of future graphene-based devices, and might provide new possibilities for manipulating the material properties of graphene.

In this field my group have systematically investigated the defect properties and growth mechanisms of CVD-grown graphene using computational techniques across both length and time scales. We employed ab initio calculations for graphene CVD growth mechanism, molecular dynamics simulations for structural and mechanical properties of defective graphene, long-time-scale accelerated dynamics simulations for dynamic properties of graphene defects, and continuum level modeling for thermal transport properties. In the molecular dynamics simulations and continuum modeling parts, I collaborated with Prof. Chien-Cheng Chang at National Taiwan University and co-advised one Ph.D. student and one M.S. student. In this field I have published eight papers, including three papers in the journal CARBON, and two papers in the Applied Physics Letters. In addition, the Ph.D student I co-advised with Prof. Chien-Cheng Chang, Dr. Te-Huan Liu, won the
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in 2012.