THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING

GEORGIA INSTITUTE OF TECHNOLOGY

Under the provisions of the regulations for the degree

DOCTOR OF PHILOSOPHY

on Wednesday June 6, 2018

9:30 AM
in MoSE 4100F

will be held the

DISSERTATION PROPOSAL DEFENSE

for

Jing Zhou

" Modulated Optical Behavior of Nanostructured Electrochromic Conjugated Polymer Hybrids"

Committee Members:

Prof. Vladimir Tsukruk, Advisor, MSE

Prof. John Reynolds, Chem/MSE

Prof. Zhiqun Lin, MSE

Prof. Dong Qin, MSE

Prof. Natalie Stingelin, MSE/ChBE

Abstract:

Down-scaling of photonics from micrometer scale to sub-wavelength scale is demanding for the integration of photonic and electronic circuits, which may lead to miniaturization of devices, higher storage capacities, and faster data transfer.  Optical inorganic nanostructures such as noble metal nanoparticles and semiconducting quantum dots are promising building blocks due to their unique light-matter interaction at the nanoscale.  Active control of these interactions in a dynamic and reversible manner is one of the key challenges for future integrated circuits where the optical signals need to be modulated for data processing.  Electrochromic conjugated polymers (ECPs), in which the color changes when the electrochemical reaction driven by an applied potential occurs, can serve as mediating matrices for tailoring light-matter interactions.  This proposal aims to understand the on-command optical behavior of nanostructured ECP/inorganic nanoparticle interfaces with electrochemically modulated light absorption and emissive properties.  ECPs with different conjugated architectures, absorbance, pendant functional groups as well as orthogonal solubilities will be considered from a viewpoint of their morphology, supramolecular organization, redox state, and balance of electronic and ionic conductivities in close proximity to inorganic interfaces of noble metal nanoparticles and semiconducting quantum dots.

Specifically, thin interfacial layers of ECPs will be fabricated around noble metal nanoparticles and functionalized quantum dots by employing various assembly methods including surface confined oxidative polymerization and layer-by-layer assembly.  Special attention will be paid to interfacial morphologies of the nanostructured assembly in order to determine the extent and mode of ECP-nanoparticle interactions.  Finally, the dynamic optical behavior of individual and aggregated ECP hybrids including absorbance, scattering, photoluminescence and photophysical properties during the electrochemical switching of ECPs will be systematically investigated.  The outcome of this research can be used to leverage the design of functional devices with large modulation of plasmon resonances and quantum dot photoluminescence, which holds promise for applications such as optical nanocircuits, full color displays, and chemical and biological sensors.