Phonon-Enhanced Mid-Infrared CO2 Gas Sensing Using Boron Nitride Nanoresonators

• DOI: 10.1021/acsphotonics.1c01254
• Publication Date: 2022-01-05T20:49:36Z
• Authors: Nestor Jr. Bareza; Bruno Paulillo; Tetiana M. Slipch...; Marta Autore; Irene Dolado; Song Liu; James H. Edgar; Saül Vélez; Luis Martín-Moreno; Rainer Hillenbrand; Valerio Pruneri
• Keywords: Thermal Stability

Hexagonal boron nitride (hBN) hosts long-lived phonon polaritons, yielding a strong mid-infrared (mid-IR) electric field enhancement and concentration on the nanometer scale. It is thus promising material for highly sensitive mid-IR sensing spectroscopy. In addition, hBN possesses high chemical thermal stability as well mechanical durability, making it suitable operation in demanding environments. this work, we demonstrate CO2 gas sensor exploiting polariton (PhP) modes nanoresonators functionalized by thin CO2-adsorbing polyethylenimine (PEI) layer. We find that PhP resonance shifts to lower frequency, weakens, broadens increasing concentrations, which are related change of permittivity PEI upon adsorption. Moreover, exhibits signal-to-noise ratio even small ribbon arrays 30 × μm2. Our results show potential become novel platform miniaturized phonon-enhanced SEIRA sensors.