<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><!--StartFragment--><p class="MsoTitle" style="margin-right:-.5in"><span style="font-family:"Times New Roman""><b><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Seminar
on<o:p></o:p></span></font></b></span></p><p class="MsoTitle" style="margin-right:-.5in"><span class="Apple-style-span" style="letter-spacing: 2px; "><b><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Modern Optics and Spectroscopy</span></font></b></span></p>
<div class="MsoNormal"><span style="font-family: Arial; letter-spacing: 1pt; "><b><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"> <o:p></o:p></span></font></b></span></div><p class="MsoBodyText" style="margin-right:-29.9pt"><span style="color: black; font-style: normal; "><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Characterization of graphene nanoribbons and
graphene edges by Raman spectroscopy and TEM</span></font></span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span style="color: black; font-style: normal; "><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"></span></font></span><b><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Xiaoting Jia</span></font></b><span style="letter-spacing: 1pt; "><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">,</span></font></span><span class="Apple-style-span" style="font-size: 14px; letter-spacing: 1px; ">Massachusetts Institute of
Technology</span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span class="Apple-style-span" style="font-size: 14px; letter-spacing: 1px; "></span><span class="Apple-style-span" style="font-size: 14px; letter-spacing: 1px; ">Tuesday, April 26, 2011</span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span class="Apple-style-span" style="font-size: 14px; letter-spacing: 1px; "></span><span class="Apple-style-span" style="font-size: 14px; letter-spacing: 1px; ">12:00 – 1:00 p.m.</span></p><p class="MsoNormal" style="text-align:justify"><span style="font-family: Arial; color: navy; "><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"> <o:p></o:p></span></font></span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span style="font-family:Helvetica"><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Graphene nanoribbons
(GNRs) are quasi one dimensional structures which have<o:p></o:p></span></font></span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span style="font-family:Helvetica"><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">unique transport
properties, and have a potential to open a bandgap at small ribbon widths. They
have been extensively studied in recent years due to their high potential for
future electronic, optical and spintronic device applications. The edge
structures - including the edge roughness and chirality- dramatically affect
the transport, electronic, optical, and magneticproperties of GNRs, and are of
the critical importance. I will first review thecurrent status and challenges
in the graphene edge study, and then discuss aboutcharacterization of the edges
using Raman spectroscopy, transmission electronmicroscopy (TEM) and scanning
tunneling microscopy (STM). I will also introduce an effective way to modify
the edges structures, and to produce atomically smooth zigzag and armchair
edges by using in-situ TEM with a controlled bias. This work provides us with
many opportunities for both fundamental studies and for future applications.</span></font></span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span style="font-family:Helvetica"><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"></span></font></span><span class="Apple-style-span" style="font-size: 14px; ">Grier Room, MIT Bldg 34-401</span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span class="Apple-style-span" style="font-size: 14px; "></span><span class="Apple-style-span" style="font-size: 14px; ">Refreshments served after the lecture</span></p><p class="MsoNormal" align="center" style="text-align:center"><o:p></o:p></p>
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