Ultralong copper phthalocyanine nanowires with new crystal structure and broad optical absorption.
The development of molecular nanostructures plays a major role in emerging organic electronic applications, as it leads to improved performance and is compatible with our increasing need for miniaturization. In particular, nanowires have been obtained from solution or vapor phase and have displayed high conductivity or large interfacial areas in solar cells. In all cases however, the crystal structure remains as in films or bulk, and the exploitation of wires requires extensive postgrowth manipulation as their orientations are random. Here we report copper phthalocyanine (CuPc) nanowires with diameters of 10-100 nm, high directionality, and unprecedented aspect ratios. We demonstrate that they adopt a new crystal phase, designated eta-CuPc, where the molecules stack along the long axis. The resulting high electronic overlap along the centimeter length stacks achieved in our wires mediates antiferromagnetic couplings and broadens the optical absorption spectrum. The ability to fabricate ultralong, flexible metal phthalocyanine nanowires opens new possibilities for applications of these simple molecules.
Wang
Hai
H
Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, London WC1E 6BT, UK.
Mauthoor
Soumaya
S
Din
Salahud
S
Gardener
Jules A
JA
Chang
Rio
R
Warner
Marc
M
Aeppli
Gabriel
G
McComb
David W
DW
Ryan
Mary P
MP
Wu
Wei
W
Fisher
Andrew J
AJ
Stoneham
Marshall
M
Heutz
Sandrine
S