“Functionalization and Chemical
                  Properties of Graphene”
  
Ø ♦ Speaker :토토 바카라Prof. Sunmin Ryu [Kyung Hee University]  
Ø ♦ Place : Physics Seminar Room (Science Bldg, 3-201)
Ø ♦ Date & Time : Nov, 25(Wed)토토 바카라3:00토토 바카라~토토 바카라4:00 pm

Abstract
  
Atom-thick graphene membrane holds substantial potential for applications in future molecular-scale
integrated electronics, transparent토토 바카라conducting토토 바카라membranes,토토 바카라nanocomposites,토토 바카라etc.토토 바카라To토토 바카라realize토토 바카라this
potential, chemical properties of graphene need to be understood and토토 바카라functionalization토토 바카라toolkits토토 바카라are
also required. To meet this need,토토 바카라surface토토 바카라chemistry토토 바카라of토토 바카라graphene토토 바카라has토토 바카라been토토 바카라explored토토 바카라by토토 바카라Raman
spectroscopy, AFM and STM scanning probes. In the first part of the talk, two chemical reactions of
graphene will be presented.토토 바카라Hydrogenation,토토 바카라the토토 바카라simplest토토 바카라basal토토 바카라plane토토 바카라functionalization,토토 바카라is토토 바카라highly
reversible and strongly dependent on the thickness of graphene in the rate. Graphene sheets can be
locally hydrogenated with a high spatial resolution. Thermal oxidation also proceeds at a higher토토 바카라rate
for single layer than double layer토토 바카라graphene and triple layer graphene behaves like bulk graphite. The
second part of the talk will illustrate the influence of underlying silicon dioxide substrates and ambient
gases on properties of graphene. Raman spectroscopy shows that freestanding graphene is essentially
charge-neutral implying that the “usual” hole-doping토토 바카라in토토 바카라supported토토 바카라graphene토토 바카라is토토 바카라mediated by oxide
substrates. An STM study토토 바카라reveals토토 바카라that토토 바카라thermal토토 바카라annealing토토 바카라generates토토 바카라out-of-plane토토 바카라deformation토토 바카라of
nanometer-scale wavelength and distortion in sp2 bonding on an atomic scale. Graphene토토 바카라deformed
by annealing is found to be chemically active enough to토토 바카라bind토토 바카라molecular oxygen,토토 바카라which토토 바카라leads t o토토 바카라a
strong hole-doping. A possible form of oxides will be discussed.
  
  
          Contact Person : Prof. Nam Ki Lee (054-279-2097, nklee@postech.ac.kr)