Wavelength-Selective Photothermal Infrared Sensors

Abstract

AbstractWavelength-specific thermal absorbers and emitters, or spectroscopic energy transducers for infrared (IR) light, are expected to provide a wide variety of applications in energy harvesting and remote and perceptive sensors for internet of things (IoT) devices. In particular, narrowband perfect absorption and emission in the IR region are critical prerequisites for modern spectroscopy and energy applications, such as nondispersive infrared (NDIR) gas sensors (fixed-wavelength infrared gas sensors), multiwavelength pyrometers, IR radiative heaters/coolers, and thermo-photovoltaics. The technology to control thermal emission and absorption has recently been rapidly progressing with the development of nanotechnologies, especially in the fields of plasmonics and metamaterials. In this chapter, we demonstrate our methodology to achieve narrowband perfect absorption and signal transduction based on 2D and 3D nanoarchitectures combined with IR plasmonic materials. We introduce some of our recently developed uncooled IR detectors combined with spectroscopic perfect absorbers for wavelength-selective IR ray detection. The 2D plasmonic IR sensors with pyroelectric detectors exhibit resolution better than 1 µm with wide acceptance angles. By adopting Wood’s anomaly plasmonic lattice structures composed of periodic microdisc arrays, a wavelength resolution as high as 51 nm (quality factor of 73) was achieved at an operation wavelength of 3.7 µm in the mid-IR region. The device could lead to the realization of a variety of new products, such as miniature spectroscopic IR devices for true-temperature pyrometry, gas imaging, position and motion sensing with high angular resolution, material-specific imaging, and environmental sensing.KeywordsThermal radiationUncooled infrared sensorsPerfect absorptionRadiative heatingPlasmonsMetamaterials