Spectroscopic Evidence of Work Function Alterations
Due to Photoswitchable Monolayers on Gold Surfaces
- Publication date
- Publisher
Abstract
Taking advantage of surfaces’
response to interfacial dipoles,
a class of photochromophores (dihydroindolizine) is demonstrated to
alter the work function of the underlying substrate (∼170 meV).
This same molecule also provides spectroscopic signatures for correlating
the change in molecular structure to the induced change in the surfaces’
electronic properties. Polarization modulation infrared reflection
absorption spectroscopy (PM-IRRAS) allows analysis of the characteristic
dihydroindolizine CC (1559 cm<sup>–1</sup>) and pyridinium
(1643 cm<sup>–1</sup>) stretch as a function of photoexcitation.
Structural assignments of this photochromophore are corroborated to
density function theory calculations. Conformational changes in the
monolayers appear in parallel with work function changes and are consistent
with both its rate and magnitude