Invited: From Graphene to Transition-Metal Dichalcogenide (TMDs) Semiconductors: Probing at Atomic Scale

Tuesday, 7 October 2014: 15:20
Expo Center, 1st Floor, Universal 7 (Moon Palace Resort)
M. Pan (Center for Nanophase Materials Sciences, Oak Ridge National Laboratory)
Doping is an efficient way to tailor the electronic, chemical, optical and magnetic properties of two-dimensional materials. Although some attention has been paid to the synthesis and potential applications of doped graphene, the nature of the dopants, e.g. the bonding type, the dopant location and the induced perturbation in the graphene lattice, are important to both basic research and practical applications, have not been fully understood. Here, we explored the synthesis of large-area, highly-crystalline monolayer doped graphene sheets via an atmospheric-pressure chemical vapor deposition (AP-CVD) method, and yielding unique types of dopants. Scanning tunneling microscopy/spectroscopy (STM/S) is presently used to explore in-depth intertwined electronic and structural phenomena on doped graphene. Furthermore, with the rising of the transition-metal dichalcogenide (TMDs) materials, we extend our STM/S technique to study the layered TMDs materials by highly resolved STM/S.  These microscopic investigations, combining with theoretical calculation, transport and optical measurements of devices, lead to a wide variety of choices with different physico-chemical properties that could be used as components in electronic and sensing devices.