Electric-field-induced charge transfer between gold nanoparticle
and capping 2-naphthalenethiol and organic memory cells
Jianyong Ouyang, Chih-Wei Chu, Douglas Sieves, and Yang Yanga!
Department of Materials Science and Engineering, University of California, Los Angeles,
California 90095
sReceived 16 September 2004; accepted 2 February 2005; published online 16 March 2005d
An electrical transition, induced by a high electric field, was observed in a device consisting of a
polystyrene film containing 2-naphthalenethiol-capped Au nanoparticles sandwiched between two
Al electrodes. The current through the device changed from a charge-injection-controlled current to
a space-charge-limited current. The latter current is higher than the former by more than three orders
of magnitude at 2 V. Asymmetrical current-voltage curve was observed along the two polarity
directions for the device after the transition. This transition is attributed to an electric-field-induced
charge transfer between the Au nanoparticle and the capping 2-naphthalenethiol. The device exhibits
good stability in the high conductivity state, so it can be used as a write-once-read-many times
electronic memory. © 2005 American Institute of Physics. fDOI: 10.1063/1.1887819g
Nanomaterials exhibit peculiar electrical, optical, and
magnetic properties different
from atoms and bulk.
Nanometer-sized electronic materials are especially interest-
ing due to quantum confinement of electrons in nanometer
dimensions.1–5 Physics has been discovered for nanomateri-
als, such as “Coulomb blockade”, surface-enhanced Raman
spectroscopy, and a size-controlled energy gap. Charge trans-
fer on metal nanoparticles has gained much attention.6–8
Optical-induced charge transfer between semiconductor
nanoparticles and polymers has been exploited in photovol-
taic cells.9,10 Recently, we observed electronic bistability in a
polymer film containing both Au nanoparticles capped with
alkanethiol and a small organic conjugated compound, and
demonstrated
its application as nonvolatil