Intraribbon heterojunction formation in ultranarrow graphene nanoribbons.
Graphene nanoribbons-semiconducting quasi-one-dimensional graphene structures-have great potential for the realization of novel electronic devices. Recently, graphene nanoribbon heterojunctions-interfaces between nanoribbons with unequal band gaps-have been realized with lithographic etching techniques and via chemical routes to exploit quantum transport phenomena. However, standard fabrication techniques are not suitable for ribbons narrower than ~5 nm and do not allow to control the width and edge structure of a specific device with atomic precision. Here, we report the realization of graphene nanoribbon heterojunctions with lateral dimensions below 2 nm via controllable dehydrogenation of polyanthrylene oligomers self-assembled on a Au(111) surface from molecular precursors. Atomistic simulations reveal the microscopic mechanisms responsible for intraribbon heterojunction formation. We demonstrate the capability to selectively modify the heterojunctions by activating the dehydrogenation reaction on single units of the nanoribbons by electron injection from the tip of a scanning tunneling microscope.
EMPA, Swiss Federal Laboratories for Materials Science and Technology, nanotech@surfaces Laboratory, 8600 Dübendorf, Switzerland.
Stephan
S
Blankenburg
Jinming
J
Cai
Pascal
P
Ruffieux
Rached
R
Jaafar
Daniele
D
Passerone
Xinliang
X
Feng
Klaus
K
Müllen
Roman
R
Fasel
Carlo A
CA
Pignedoli
D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006865:Hydrogenation; D008958:Models, Molecular; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011789:Quantum Theory; D013499:Surface Properties
D037742:Nanotubes, Carbon; D011108:Polymers; D006046:Gold; D006108:Graphite