Graphene-Base Hot-Electron Transistor
Dec 12, 2013
from 10:00 AM to 12:00 PM
|Where||Engr. IV Bldg, Faraday Room 67-124|
|Contact Name||Caifu Zeng|
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Advisor: Prof. Kang L. Wang
The exceptional properties of the two-dimensional material, graphene, having high-mobility carriers, deployable on a large area have made it attractive for RF electronic applications. However, the channel mobility in graphene-channel field effect transistor (GFET) is still limited by various external scattering sources and the absence of a bandgap in graphene causes poor current on-off ratio in GFETs. Graphene-base hot-electron transistor (GB-HET) uses the single-atomic thick, semi-metallic graphene as the base region of the hot-electron transistor. It provides an alternative way to utilize the unique properties of graphene and solve the problems of the GFET from the fundamental operational principle. This talk focuses the operational principle, fabrication and characteristics of a variety of GB-HETs. The GB-HETs exhibit a current saturation with a high on-off ratio in the current-voltage characteristics. The influences of the materials and their thicknesses used for the tunnel-barrier and filter-barrier of a GB-HET are investigated. The common-base current gain, α, are improved by more than two orders of magnitude by optimizing the device parameters.
Caifu Zeng is a Ph.D. candidate in Electrical Engineering Department at University of California, Los Angeles. He receives the B.S. degree in Electrical Engineering from Zhejiang University, China in 2007, the M.S. degree in Electrical Engineering from UCLA in 2009. His research interests are in graphene-related nano-electronics.