am0c01562_si_001.pdf (2.88 MB)
Electrochemical Switching of Plasmonic Colors Based on Polyaniline-Coated Plasmonic Nanocrystals
journal contribution
posted on 2020-03-31, 13:03 authored by Wenzheng Lu, Tsz Him Chow, Sze Nga Lai, Bo Zheng, Jianfang WangPlasmonic color generation
has attracted much research interest
because of the unique optical properties of plasmonic nanocrystals
that are promising for chromatic applications, such as flat-panel
displays, smart windows, and wearable devices. Low-cost, monodisperse
plasmonic nanocrystals supporting strong localized surface plasmon
resonances are favorable for the generation of plasmonic colors. However,
many implementations so far have either a single static state or complexities
in the particle alignment and switching mechanism for generating multiple
displaying states. Herein, we report on a facile and robust approach
for realizing the electrochemical switching of plasmonic colors out
of colloidal plasmonic nanocrystals. The metal nanocrystals are coated
with a layer of polyaniline, whose refractive index and optical absorption
are reversibly switched through the variation of an applied electrochemical
potential. The change in refractive index and optical absorption results
in the modulation of the plasmonic scattering intensity with a depth
of 11 dB. The electrochemical switching process is fast (∼5
ms) and stable (over 1000 switching cycles). A device configuration
is further demonstrated for switching plasmonic color patterns in
a transparent electrochemical device, which is made from indium tin
oxide electrodes and a polyvinyl alcohol solid electrolyte. Our control
of plasmonic colors provides a favorable platform for engineering
low-cost and high-performance miniaturized optical devices.