摘要：
Graphene, a monolayer of carbon atoms forming a two-dimensional honeycomb lattice structure, is considered a wonder material for both scientific research and technological applications since its successful isolation in 2004. As a flexible, transparent conductor with intrinsically very high electrical mobility and thermal conductivity, graphene is promising for large-area electronic devices such as touch screen displays, electrodes for photovoltaic cells and panels for light emitting diodes. Its unique electronic, thermal and mechanical properties and compatibility with two-dimensional lithographic techniques are also ideal for many nano-electronic, spintronic and mechanical applications. However, a major challenge to fully realize the potential of graphene-based technologies is to reproducibly fabricate large-area high-quality graphene. Here we show a new method that employs plasma-assisted chemical vapor deposition (CVD) techniques for producing high-quality large-area (~ 1 cm2) monolayer graphene on copper at room temperature (RT). Studies of these samples by scanning tunneling microscopy (STM) and Raman spectroscopy confirm excellent crystalline quality and much reduced strain of the RT-grown graphene on Cu foils, Cu (100) and Cu (111) single crystals relative to samples grown with the standard CVD techniques at 1000 C. Atomic force microscopy (AFM) studies also revealed significantly larger grain sizes of the RT-grown graphene, and the large sheets remained intact upon transferred from copper to other substrates, suggesting excellent mechanical integrity. Further, electrical transport measurements of the RT-grown graphene exhibited high mobility and quality transport characteristics. Our findings therefore shed new light on the growth kinetics of graphene and open up a new pathway to large-scale, high-quality and inexpensive graphene fabrication for scientific research and technological applications.

报告人简介：
Nai-Chang Yehcurrentlyholds the position of Professor of Physics at California Institute of Technology (Caltech). She received her B.Sc. degree in Physics from National Taiwan University in 1983 and Ph.D. degree in Physics from MIT in January 1988. From January 1988 to August 1989, she was a visiting scientist at IBM, Thomas J. Watson Research Center, and she joined the Caltech faculty in August 1989,subsequently became the first woman professor tenured in physics at Caltech in 1995. Her principal research field is experimental condensed matter physics, with special emphasis on correlated electronic systems (such as high-temperature superconductivity, novel magnetism andspintronics), topological materials (including graphene and related nano-structures, topological insulators and topological superconductors), and nano-science and nano-technology. Her professor honors include: Wu Chien-Shiung Distinguished Lectureship, National Central University, Taiwan; Fellow, American Association for the Advancement of Science; Fellow, American Physical Society; Distinguished Alumni Award, Department of Physics, National Taiwan University; Fellow, The Institute of Physics, UK; Achievement Awards, Southern California Chinese-American Faculty Association; Outstanding Young Researcher Award, Overseas Chinese Physics Association; Packard Fellowship for Science and Engineering; Sloan Research Fellowship; and Luise Meyer-Schutzmeister Memorial Award.