April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
EL08.17.07

Engineering Chiral Plasmonic Nanocrystals via Controllable Photoetching of Silver Nanorods with Circularly Polarized Light

When and Where

Apr 26, 2024
2:45pm - 3:00pm
Room 340/341, Level 3, Summit

Presenter(s)

Co-Author(s)

Tian Qiao1,Tsumugi Miyashita1,Anne Ashworth1,MingLee Tang1

The University of Utah1

Abstract

Tian Qiao1,Tsumugi Miyashita1,Anne Ashworth1,MingLee Tang1

The University of Utah1
Chiral plasmonic nanostructures have shown great potential for photonics and sensing applications. Chiral molecules and micelles have been demonstrated to be effective sources of chirality, enabling the colloidal production of large-scale, homogeneous chiral plasmonic nanocrystals. Recent investigations have explored the use of circularly polarized light (CPL) as a chirality source to fabricate chiral Au/PbO<sub>2</sub> heterostructures or as an additional ingredient in chiral molecule-directed synthesis to enhance the optical dissymmetry of the nanocrystals further. However, the mechanism by which these chiral structures develop with CPL has remained largely unexplored. Our latest study has revealed that the wavelength of CPL is a critical factor in determining the shape of chiral Au/PbO<sub>2</sub> heterostructures and their resulting chiroptical properties. Here, we further demonstrate that the asymmetry of the initial plasmonic nanocrystals plays a crucial role in generating more chiral nanostructures. Specifically, we utilized silver nanorods with varying aspect ratios as the starting materials. Ag was oxidized at selective sites upon circularly polarized excitation to create chiral structures. Our results indicate that the optical activity of resulting chiral nanostructures increases with the aspect ratio of the starting nanocrystals. Besides, tuning the excitation wavelength with Ag nanorods of a larger aspect ratio can yield higher contrast of chiral morphologies due to the larger number of higher-order modes accessible in these nanocrystals. Our study underscores the importance of carefully selecting the starting material and excitation wavelength to maximize chiral plasmonic nanocrystals' shape and optical dissymmetry when using CPL as the chirality source. Besides, the non-toxic chiral Ag nanocrystals are more suitable for bio-compatible systems than chiral Au/PbO<sub>2</sub> nanostructures.

Keywords

nanostructure

Symposium Organizers

Yao-Wei Huang, National Yang Ming Chiao Tung University
Min Seok Jang, Korea Advanced Institute of Science and Technology
Ho Wai (Howard) Lee, University of California, Irvine
Pin Chieh Wu, National Cheng Kung University

Symposium Support

Bronze
APL Quantum
Kao Duen Technology Corporation
Nanophotonics Journal

Session Chairs

Boubacar Kante
Ho Wai (Howard) Lee

In this Session