Electromagnetic Field Enhancement of Nanostructured TiN Electrodes Probed with Surface-Enhanced Raman Spectroscopy

Abstract

We present a facile approach for the determination of the electromagnetic field enhancement of nanostructured TiN electrodes. As model system, TiN with partially collapsed nanotube structure obtained from nitridation of TiO2 nanotube arrays was used. Using surface-enhanced Raman scattering (SERS) spectroscopy, the electromagnetic field enhancement factors (EFs) of the substrate across the optical region were determined. The non-surface binding SERS reporter group azidobenzene was chosen, for which contributions from the chemical enhancement effect can be minimized. Derived EFs correlated with the electronic absorption profile and reached 3.9 at 786 nm excitation. Near-field enhancement and far-field absorption simulated with rigorous coupled wave analysis showed good agreement with the experimental observations. The major optical activity of TiN was concluded to originate from collective localized plasmonic modes at ca. 700 nm arising from the specific nanostructure.

A Review on Nano Ti-Based Oxides for Dark and Photocatalysis: From Photoinduced Processes to Bioimplant Applications

“…Furthermore, even structures obtained from TNA somehow retain the light enhancement afforded by the 2D periodic arrangement of the nanotubes ( Figure 6 c). For example, nitridation of the TNA resulting in a partially collapsed nanotube structure of TiN also shows wavelength-dependent EM field enhancement and corresponding light enhancement [ 177 ].…”

“…The EF scale bars are shown at the left of the images. Adapted with permission from [ 177 ]. Copyright 2022 by the authors.…”

Chiro-plasmon responses of x-shaped titanium nitride (TiN) nanoarrays by numerical simulations

“…In the last decade, titanium nitride (TiN) has attracted growing interest in solar cell [19], surface plasmon enhanced Raman scattering [20,21], and plasmon sensing [22], etc The broad application of TiN associates closely with its strong potential candidate to substitute traditional plasmon material of gold and silver due to the high melting point, thermal stability, and compatibility with CMOS technology. It benefits from the low-loss plasmon characteristic of TiN-like materials, whose plasmon properties originate from the complex balance between intraband and interband transitions acting as the screening term of global electron gas [23].…”

“…Moreover, TiN is revealed to exhibit similar optoelectronic properties to Au to many extent, including the low imaginary part of the dielectric function, although not zero, and the low-energy plasmon excitation. This allows its adjustable localized surface plasmon resonance from visible to NIR band by the geometry of TiN nanostructure and dielectric environments [19][20][21][22][23]. Yet, literature reports about plasmonic chirality are noted to focus on noble metal metamaterials while TiN metamaterials are still limited [24][25][26][27][28].…”

Adjustment of eccentricity and split angle for improved SERS and refractive index sensing of TiN nanodonuts

“…Owing to its excellent complementary metal-oxide semiconductor (CMOS) compatibility, chemical stability, and thermal stability, titanium nitride (TiN), which has a melting point of 2,930 °C and high-temperature durability, has been demonstrated to provide a unique refractory plasmon substitute for noble metals [1][2][3][4][5][6][7][8][9][10][11]. With appropriate incident illumination, the free electrons of TiN nanoparticle surfaces can also be collectively excited to form localized surface plasmon resonances (LSPRs) similar to those of Au/Ag, which are broadly adjustable from visible to near-infrared regions [4][5][6][7][8][9][10][11]. This can be performed by tuning the detailed nanoparticle geometry and their surrounding medium refractive index (RI).…”