NORTH CAROLINA STATE UNIVERSITY
DEPARTMENT OF PHYSICS
Organic Electronic Materials
Overview
Organic molecules are used in a variety of thin-film
devices such as new high-definition television sets.
Future organic electronics may have new functionality
such as in solar cells for electrical power and spindependent properties with higher performance. An
important advantage of organic-molecule devices is
the ability to manufacture devices with methods easily
compatible with existing manufacturing and therefore
the possibility of new features at lower cost than
previous generations of devices. However, there is a
need for better understanding of the fundamental
physics of the device mechanisms of organicmolecule systems. This research is being carried out
by members of the organic electronic materials group
at NC State.
Harald Ade
Photovoltaics are well known and promising
technologies to solve future energy needs and to,
maybe more importantly, reduce emissions of CO2, a
major greenhouse gas. In several tens of minutes,
energy from the sun is enough to cover the yearly total
requirement for the world. The potential of
photovoltaics is even larger than that of biofuels, as
arid areas can be successfully utilized for energy
creation. The Ade research group is using advanced
synchrotron radiation based characterization tools,
such as X-ray microscopy and resonant scattering, to
better understand the function of organic solar cells.
Faculty Members and Research Interests
Kenan Gundogdu
Prof. Gundogdu’s research focuses on the study of
electron dynamics in organics and their interfaces with
inorganic materials. Ultrafast optical techniques are
used to characterize electronic coupling, charge
transfer, exciton diffusion, and many body
interactions with femtosecond time resolution. These
studies quantify how interface morphology and
electronic energy level alignments impact dynamics,
which are very important for organic optoelectronic
device structures. ([email protected])
Interactions between nuclear spins in complex
molecules (A,B) and between oppositely spin polarized
electron hole pairs in a semiconductor (C).
.NC STATE Physics.
Additionally, the advanced synchrotron radiation tools
are used to characterize organic light emitting diodes
and organic thin film transistors. The Ade group is a
world leader in the development and use of these
methods. ([email protected])
Dan Dougherty
Prof. Dougherty’s research group focuses on
measurements of the local electronic properties of
nanostructured surfaces using ultrahigh vacuum
scanning tunneling microscopy and spectroscopy. A
significant fraction of this work addresses how
molecular self-assembly at interfaces and molecular
www.physics.ncsu.edu
structure in films determines the energies of electronic
transport states. In addition, the group has developed
the capability to carry out spin polarized STM/STS for
the purpose of understanding the interaction between
magnetic surfaces and adsorbed molecules. These
fundamental experiments provide the scientific
foundation for optimizing applications of organic
molecular materials in electronic and spintronic
devices. ([email protected])
J. E. (Jack) Rowe
Prof. Rowe’s group uses measurements that include
scanning tunneling microscopy (STM), atomic force
microscopy (AFM), low energy electron diffraction
(LEED); soft X-ray photoemission spectroscopy
(SXPS) including results with synchrotron radiation
(SR-SXPS) and with spin detection. A major goal of
this research program is to study the initial surface and
buried-interface processes of electronic materials at
the nanoscale. Photoemission-based methods can
measure threshold energy barriers (sometimes these
are spatially resolved). One example of these studies
is the organic-molecule system of a nickel
phthalocyanine (NiPc) film on a Au(001) surface.
SR-SXPS results from these studies are shown in the
figure below. The HOMO (2a1u) shifts between 1.4
and 3 Å indicates that the barrier is not fully formed
until ~3 Å. Future experiments will also measure XPS
levels such as C-1s, Ni-2p, and Au-4f.
([email protected])
Constant current tunneling spectrum (tip displacement
versus gap voltage) showing the π* derived resonance
of a single Alq3 molecule on Cu(110). Inset is a quantum
mechanical calculation of the π* orbital shape.
ARUPS valence orbitals of NiPc on a Au(001) surface at
~300 K. Bottom vertical lines show gas-phase data IP’s.
Self assembled monolayer of benzoate on Cu(110)
Further Information
We encourage interested applicants to learn more by visiting the faculty web pages. Prospective students can contact
any faculty member directly (see email addresses above) or the Graduate Program office at [email protected].
.NC STATE Physics.
www.physics.ncsu.edu