Synthesis of High-Quality Two-Dimensional Materials for New Functional Devices

Abstract:

Two-dimensional (2D) materials, such as graphene, hexagonal boron nitride (h-BN), transition metal dichalcogenides (TMDs), topological insulators (TIs), and the more recent silicene and germanene, etc., have stable crystalline structures and unique electronic properties, representing the new frontier of advanced materials research. The synthesis of high-quality and large-area 2D materials is thus of critical importance both in basic science and in real applications. As the first truly 2D material, graphene continues to stay in the spotlight and has become a paradigm in this field. In this talk I will discuss the synthesis of large single crystalline monolayer (centimeter scale) and bilayer graphene (millimeter scale) using chemical vapor deposition, which show superior electronic performance comparable to those exfoliated from natural graphite. Detailed growth kinetics study combining experimental and theoretical efforts has revealed the rich physics behind the intriguing growth phenomena, and sheds insight into future routes for synthesizing other 2D materials, such as TMDs, TIs, and vertical/lateral 2D heterostructures with high crystalline quality at large scale. Scalable synthesis of these new 2D materials is expected to lead to revolutionary applications in electronic, photonic, and energy harvesting devices and systems.

Biography:

Dr. Yufeng Hao is currently an Associate Research Scientist in the Columbia Nano Initiative and Department of Mechanical Engineering at Columbia University. He earned his Ph.D. in Materials Physics and Chemistry from the Institute of Solid State Physics, Chinese Academy of Sciences. He did postdoctoral studies at National University of Singapore and then at the University of Texas at Austin. Yufeng has extensive research experience in synthesis, characterizations, and electronic device measurements of one-dimensional and 2D materials. His recent research is particularly focused on the synthesis and transfer of 2D materials, such as graphene and TMDs, and made significant contributions in producing high-quality samples and building up 2D materials growth mechanisms. Dr. Hao has published over 60 journal papers in prestigious journals, such as Science, Nature, Nature Nanotechnology, Physical Review Letters, etc. These publications have achieved more than 3200 citations, and his H-index is 30.