Princeton University

School of Engineering & Applied Science

Disc-Coupled Dots-on-Pillar Antenna Array (D2PA) as a Nanoplasmonic Structure and its Application

Speaker: 
Fei Ding
Location: 
Engineering Quadrangle J401
Date/Time: 
Wednesday, November 16, 2016 - 2:00pm to 3:30pm

Abstract
Nanoplasmonic structures have been developed for decades, and are widely used in many fields, like surface enhanced linear/non-linear optical process (e.g. surface enhanced Raman scattering (SERS), surface enhanced fluorescence, surface enhanced second harmonic generation, and surface enhanced up-conversion), coloring, energy harvest, heat generation, and so on. Conventional nanoplasmonics, e.g. nanoparticles and antennas, suffer from low, non-uniform, and non-repeatable filed enhancement, as well as fabrication difficulties, including precision (e.g. precision requirements of shape, gap, and sharp tips are beyond lithography limitation) and throughput (e.g. serial fabrication is impractical for mass fabrication). It blocks the way to applications outside labs.
In 2009, Prof. Stephen Y. Chou proposed and demonstrated a novel nanoplasmonic structure, Disc-coupled Dots-on-Pillar Antenna Array (D2PA), with high enhancement, good uniformity, and large area mass fabrication method. In this thesis, we highlight D2PA structure optimization, as well as its application in SERS.
In the first part, (1) disc shape is tuned with a new fabrication method, multiple double nanoimprint lithography, which is an EBL free method to create nanostructure array with continuous varying shape, spacing, and density. Sub-1.0nm linear tuning is achieved in experiments. (2) Dots-on-pillar are optimized with pillar surface energy, as well as growth condition. (3) near-field performance is studied with ultra-thin layer dielectric coating.
The second part features the systematic study of non-monotonic intensity-concentration relationship, which exists in many SERS measurements, and a model based on molecular orientation is proposed and experimentally verified to address this phenomenon.