Non-dispersive infrared multi-gas sensing via nanoantenna integrated narrowband detectors

Xiaochao Tan,Houbin Zhu,Heng Zhang,Junyu Li,Huan Liu,Qiushi Guo,Haowei Wan,Fei Yi

doi:10.1038/s41467-020-19085-1

Abstract

Non-dispersive infrared (NDIR) spectroscopy analyzes the concentration of target gases based on their characteristic infrared absorption. In conventional NDIR gas sensors, an infrared detector has to pair with a bandpass filter to select the target gas. However, multiplexed NDIR gas sensing requires multiple pairs of bandpass filters and detectors, which makes the sensor bulky and expensive. Here, we propose a multiplexed NDIR gas sensing platform consisting of a narrowband infrared detector array as read-out. By integrating plasmonic metamaterial absorbers with pyroelectric detectors at the pixel level, the detectors exhibit spectrally tunable and narrowband photoresponses, circumventing the need for separate bandpass filter arrays. We demonstrate the sensing of H2S, CH4, CO2, CO, NO, CH2O, NO2, SO2. The detection limits of common gases such as CH4, CO2, and CO are 63 ppm, 2 ppm, and 11 ppm, respectively. We also demonstrate the deduction of the concentrations of two target gases in a mixture.

Highlights

Non-dispersive infrared (NDIR) spectroscopy analyzes the concentration of target gases based on their characteristic infrared absorption
We demonstrate that the concentrations of two target gases in a mixture can be deduced from the voltage responses of two narrowband detectors
We have presented the design, fabrication and measurement of narrowband pyroelectric detectors that are enabled by directly integrating plasmonic metamaterial absorbers onto the sensing area of lithium tantalate elements as on-chip absorption filters

Summary

Introduction

Non-dispersive infrared (NDIR) spectroscopy analyzes the concentration of target gases based on their characteristic infrared absorption. Non-dispersive infrared (NDIR) spectroscopy is one of mid-IR spectroscopic gas sensors that analyzes gases based on their characteristic absorption wavelengths in the mid-IR caused by their molecular vibrations[1,7], which can find profound applications in traced gas sensing[8,9], breadth analysis[10,11], environmental monitoring[12,13], to name a few. In order to analyze several target gases in a mixture at the same time, one can implement multiple pairs of “bandpass filter + optical detector” in the NDIR gas sensor[15,16] This scheme greatly increases the cost, the system complexity as well as the operating time, especially when the number of target gases is large[17,18]. PMA is composed of arrays of metallic plasmonic resonators that can selectively absorb a certain spectral band of light and, can be regarded as nanoscale absorption filters[19,20,21,22,23]

Methods

Results

Conclusion