Chen Wie

STM and synchrotron studies of the molecule-substrate interface
Wei Chen and Andrew Thye Shen Wee
Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542
Email: [email protected]; [email protected]
Self-assembled molecular nanostructures or organic thin films with well-defined orientation,
conformation, and two-dimensional (2D) organization on surfaces have great potential in organic
electronics, and molecular nano-devices. Their interfaces to substrates (dielectric or conducting
electrodes) and of the organic heterojunctions have the crucial impact on the device performances.
In particular, significant improvement on the power conversion efficiency of organic photovoltaic
devices, constructed from organic p-n or organic-inorganic heterojunctions, relies on the thorough
understanding as well as effective engineering of those interface properties. In this talk we will
focus on our recent results of STM and synchrotron studies of the molecule-substrate interface. We
use synchrotron-based photoemission spectroscopy (PES), near-edge x-ray absorption spectroscopy
(NEXAFS) and low-temperature scanning tunneling microscopy (LT-STM) to investigate the
molecular and organic-electronics related interface problems, including self-assembled molecular
nanostructure arrays, interface dipole formation, interface energy level alignment, supramolecular
packing and molecular orientation.1,2
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