高等研究院 Institute for Advanced Study
Ordered domain boundary defects in MBE-grown monolayer and bilayer MoSe2
Dr. Hongjun Liu, Ph.D.
University of Hong Kong.
About the speaker
Dr. Liu, Postdoctoral fellow from Physics department of The University of Hong Kong. He got bachelor and master degree from University of Science and Technology of China, and Ph.D. degree from the joint graduate school of University of Tsukuba and National Institute for Materials Science in Japan.
Ultrathin transition metal dichalcogenides (TMDs), with the common formula of MX2 (M=Mo, W; X=S, Se), are of great current interests for their potential electronic, optoelectronic and catalytic applications. Here, I present the growth and characterization of ordered linear defects in both monolayer and bilayer MoSe2 grown by molecular-beam epitaxy. These defects are identified to be inversion domain boundaries by high-resolution transmission electron microscopy and scanning tunneling microscopy and spectroscopy (STM/STS) studies. STM/STS measurements further reveal 1D mid-gap metallic states at the inversion domain boundaries and intensity undulations of the metallic modes, which are suggested to be caused from the superlattice potentials due to moiré pattern and the quantum confinement effect. A dense network of the metallic modes with high density of states is of great potential for heterocatalysis applications, and the interconnection of such mid-gap 1D conducting channels may also imply new transport behaviors distinct from the 2D bulk.
时间: 2015年4月24日 下午2：00-3：00
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