MTSE Seminar
2:00 pm, January 29th, 2016
Discovery Park, B 155
Graphene Plasmonics
Dr. Shin Mou
Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson AFB, OH, USA
Abstract
While the science and research of surface plasmon centered around metal nanoparticles blossomed and
produced in the last twenty years, people paid little attention to tunable semiconductor surface plasmon
due to the lack of suitable host materials – most of them would only show plasmon resonances in THz
under cryogenic temperature. With the emergence of graphene, a tunable semimetal under field effect,
researchers have been able to demonstrate tunable plasmon resonances at room temperature, which
enables new capabilities beyond those of metal-nanoparticle surface plasmons. In this work, we
experimentally demonstrated polarization dependent and gate-bias tunable plasmon-resonance absorption
in the mid-infrared regime of 5-14 um by utilizing an array of graphene nanoribbon resonators. By
scaling nanoribbon width and charge densities, we probed graphene plasmons with plasmon resonance
energy as high as 0.26 meV (2100 cm-1) for 40 nm wide nanoresonators. By mapping the wavevectorfrequency dispersion of graphene plasmons in mid-infrared, we demonstrated a modified graphene
plasmon dispersion resulting from the intrinsic optical phonons of graphene and the interaction of
graphene nanoresonators with the surface polar phonons in SiO2 substrates. Additionally, we studied
graphene plasmon damping by introducing charges and defects with controlled electron beam irradiation
on graphene nanoribbons. The result reveals the intriguing nature of graphene plasmon in graphene
nanoribbons where the nanoribbon edge plays critical roles by introducing extra doping and damping the
graphene plasmon resonance.
Dr. Shin Mou joined the Air Force Research Laboratory (AFRL) in
January 2011 as Research Electronic Engineer in the Materials and
Manufacturing Directorate (RX). He is currently the acting research team
lead of the Nanoscale Transport M&P research team. His research
interests are in high performance electronic and photonic materials, with
focus on graphene and other 2-dimensional materials. Between 2009 and
2011, he was a postdoctoral researcher residing at AFRL, WrightPatterson AFB. Prior to that, he was a CMOS device engineer /scientist
at IBM, Fishkill, NY. He received his Ph.D. degree in electrical and
computer engineering from University of Illinois at Urbana-Champaign
in 2007, M.S. and B.S. degrees in electrical engineering from National
Taiwan University in 1998 and 2000, respectively. His doctoral research
was on infrared photodetectors based on InAs/GaSb type-II superlattices.
He was a recipient of the National Research Council Postdoctoral
Fellowship (2009-2011.)