Plasmon-enhanced electron harvesting in robust titanium nitride nanostructures
File(s)TiON NP Annealing Paper_spiral.pdf (1.54 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Titanium nitride (TiN) continues to prove itself as an inexpensive, robust, and efficient alternative to gold in plasmonic applications. Notably, TiN has improved hot electron-harvesting and photocatalytic abilities compared to gold systems, which we recently attributed to the role of oxygen in TiN and its native semiconducting TiO2–x surface layer. Here, we explore the role of localized surface plasmon resonances (LSPRs) on electron harvesting across the TiN/TiO2–x interface and probe the resilience of TiN nanostructures under high-power laser illumination. To investigate this, we fabricate TiN strips, in which the lateral confinement allows for the polarization-selective excitation of the LSPR. Using ultrafast pump–probe spectroscopy, optical characterization, and Raman vibrational spectroscopy, we relate the differences and changes observed in the electron behavior to specific material properties. We observe plasmon-enhanced electron harvesting beyond what is expected resulting from the enhanced absorption of the plasmonic mode. We accredit this to the surface oxide damping the plasmon resonance, providing additional nonradiative loss channels. Subsequently, we show that low-power annealing of the surface oxide layer reduces the trap density at the interface and increases the initial harvested electron concentration. The unique properties of TiN make it important in the future development of plasmonic electron-harvesting applications.
Date Issued
2019-08-01
Date Acceptance
2019-07-01
Citation
The Journal of Physical Chemistry Part C: Nanomaterials and Interfaces, 2019, 123 (30), pp.18521-18527
ISSN
1932-7447
Publisher
American Chemical Society
Start Page
18521
End Page
18527
Journal / Book Title
The Journal of Physical Chemistry Part C: Nanomaterials and Interfaces
Volume
123
Issue
30
Copyright Statement
© 2019 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.jpcc.9b03184.
Sponsor
Engineering & Physical Science Research Council (E
Grant Number
EP/M013812/1
Subjects
Physical Chemistry
09 Engineering
03 Chemical Sciences
10 Technology
Publication Status
Published
Date Publish Online
2019-07-08