ARTICLE
Raman Spectroscopy of Lithographically Patterned Graphene Nanoribbons )
Sunmin Ryu,†,* Janina Maultzsch,‡ Melinda Y. Han,§,# Philip Kim,^ and Louis E. Brus
Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 446-701, Korea, ‡Institut f€ur Festk€orperphysik, Technische Universit€at Berlin, 10623 Berlin, Germany, §Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States, ^Department of Physics, Columbia University, New York, New York 10027, United States, and Department of Chemistry, Columbia University, New York, New York 10027, United States. # Current affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, United States. )
†
G
raphene has attracted much interest as a novel two-dimensional material with great potential in future applications such as flexible and transparent electrodes,13 electrical devices,4 ultrathin membranes,5 and various nanocomposites6 due to its remarkable material properties. In particular, nanometer-sized graphene objects (NGOs) are becoming more highlighted in further manipulating the inherent properties of bulk graphene sheets. Graphene nanoribbons (GNRs) have early been predicted to behave as a semiconductor with a bandgap that is determined by ribbon width and chirality.7 The dimensionbandgap correlation has been experimentally confirmed for lithographically patterned GNRs.8 Field effect transistors (FETs) made of chemically derived GNRs of width
