Events
Synthesis and Heterostructures of Monolayer Semiconductors
August 6, 2015 at 2pm/36-428
Yi-Hsien Lee
Department of Materials Science and Engineering, National Tsing Hua University, Taiwan
Abstract:
Monolayers of van der Waals (vdw) materials, such as graphene and MoS2, have been highlighted regarding both scientific and industrial aspects for novel physical phenomenon inherited from the reduced dimensionality. Layered transition metal dichalcogenides (TMD) atomic layers, being considered as the thinnest semiconductor, exhibit great potential for advanced nano-devices. Monolayer in the class of offered a burgeoning field in fundamental physics, energy harvesting, electronics and optoelectronics.
Recently, atomically thin heterostructures of TMD monolayer with various geometrical and energy band alignments are expected to be the key materials for condensed physics and next generation flexible optoelectronics. The individual TMD monolayers can be adjoined vertically or laterally to construct diverse heterostructures which are difficult to reach with the laborious pick up-and-transfer method of the exfoliated flakes. Here, we would demonstrate the synthesis of diverse monolayers and their heterostructures. Symmetry and the interface of these heterostructures were investigated using optical analysis and atomic-resolution scanning TEM. Some applications and physical phenomenon of individual TMD monolayers and their heterostructures were presented.
Bio:
Dr. Yi-Hsien Lee earned his M.S.(2001) and Ph.D. (2005) in Materials Science and Engineering from the National Tsing Hua University in Taiwan. He was a postdoc from 2006 – 2010 in the Physics department at Academia Sinica in Taiwan. In 2011, he continued as a postdoc at Academia Sinica in the Research Center of Applied Science. From 2012 – 2013, he was a postdoc in Electrical Engineering at MIT with Jing Kong’s research group. Currently, he is an Associate Professor in the Department of Materials Science and Engineering at the National Tsing Hua University. His research interests include synthesis and applications of 2D materials beyond graphene and low dimensional heterostructures.
