Obliquely Deposited Titanium Nitride Nanorod Arrays as Surface-Enhanced Raman Scattering Substrates

Abstract

In this work, titanium nitride (TiN) nanorod arrays were prepared as surface-enhanced Raman scattering (SERS) substrates using glancing angle deposition (GLAD) in a magnetron sputtering system. The nitrogen flow rate was varied from RN2 = 1 to 3 sccm, yielding five TiN uniform thin films and five TiN nanorod arrays. The figure of merit (FOM) of each TiN uniform film was measured and compared with the SERS signal of each TiN nanorod array. Rhodamine 6G (R6G) was used as the analyte in SERS measurement. For an R6G concentration of 10−6 M, the analytical enhancement factor (AEF) of the TiN nanorod array that was prepared at RN2 = 1.5 sccm was 104. The time-durable SERS performance of TiN nanorod arrays was also investigated.

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

“…700 nm were observed in the absorption spectrum (Figure 1B), indicating optical activity over a large fraction of the visible spectrum. Previous studies have reported similar absorption profiles for nanostructured TiN and attributed those to the distinct plasmonic activity of the material [1,15,28]. LSPRs of TiN created upon light illumination have been proposed to manifest as broad absorption features that are located at specific frequencies characteristic for the specific nanostructure geometry.…”

“…nanostructured TiN and attributed those to the distinct plasmonic activity of the material [1,15,28]. LSPRs of TiN created upon light illumination have been proposed to manifest as broad absorption features that are located at specific frequencies characteristic for the specific nanostructure geometry.…”

“…Titanium nitride (TiN) is an emerging substrate material for optical and sensing applications [1,2]. This low-cost plasmonic active transition metal nitride exhibits several relevant material properties, such as metal-like conductivity, high thermal and chemical stability as well as high biocompatibility, rendering TiN a unique refractory plasmonic material and potential alternative to traditionally employed plasmonic substrates, such as silver and gold [1,3,4].…”

“…Titanium nitride (TiN) is an emerging substrate material for optical and sensing applications [1,2]. This low-cost plasmonic active transition metal nitride exhibits several relevant material properties, such as metal-like conductivity, high thermal and chemical stability as well as high biocompatibility, rendering TiN a unique refractory plasmonic material and potential alternative to traditionally employed plasmonic substrates, such as silver and gold [1,3,4]. So far, TiN has been featured as a corrosion-stable electrode in bioelectronic/biomedical devices [3,4], as a support material for electrocatalysis [5] and photocatalysis [6], as a refractory metamaterial [7], as heat conversion material in thermal devices [8], as well as sensor material for optical spectroscopies [9][10][11].…”

“…TiN's intrinsic plasmonic near-field enhancement has sparked its application as a SERS substrate [25]. REFs ranging up to 10 4 have been reported for certain probe molecules loaded on TiN nanostructures [1,13,26,27]. However, in most cases the experimental parameters do not allow for a direct correlation between REF and EF, as stated by Equation (1) and thus, for drawing conclusions on the magnitude of the electromagnetic field enhancement (EME) of the respective support.…”