Spatial resolution of a type II heterojunction in a single bipolar molecule.
Bipolar molecules incorporating donor and acceptor components within a single molecule create exciting device opportunities due to their possible use as nanoscale p-n heterojunctions. Here we report a direct characterization of the internal electronic structure of a single bipolar molecular heterojunction, including subnanometer features of the intramolecular donor-acceptor interface. Angstrom-resolved scanning tunneling spectroscopy was used to map the energy levels and spatial extent of molecular orbitals across the surface of an individual bipolar molecule, bithiophene naphthalene diimide (BND). We find that individual BND molecules exhibit type II heterojunction behavior with orbital energy shifts occurring over subnanometer intramolecular interface distances. Comparison of this behavior with first-principles theoretical modeling provides new insights into the optimization of these molecular systems.
Tao
Chenggang
C
Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
Sun
Jibin
J
Zhang
Xiaowei
X
Yamachika
Ryan
R
Wegner
Daniel
D
Bahri
Yasaman
Y
Samsonidze
Georgy
G
Cohen
Marvin L
ML
Louie
Steven G
SG
Tilley
T Don
TD
Segalman
Rachel A
RA
Crommie
Michael F
MF
D003198:Computer Simulation; D007094:Imides / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D009281:Naphthalenes / Q000737:chemistry*
D007094:Imides; D009281:Naphthalenes; C542131:naphthalenediimide