Ultra-thin infrared selective emitter based on a simple micro-nano structure

The rapid development of infrared sensing technologies has increased the demand for effective regulation of thermal-radiation signatures. At present, the research on reducing the infrared radiative contrast between the object and its surroundings mainly focuses on thin film materials with low emittance in the atmospheric windows of 3–5 µm and 8–14 µm and high emittance in the non-atmospheric window of 5–8 µm, aiming to reduce the infrared radiation characteristic of objects while considering heat dissipation. Herein, we propose a novel selective emitter with broad-spectrum selective infrared radiation and thermal control capabilities. The selective emitter structure is simple, consisting of only five layers, with a total thickness of only 263.5 nm. This selective emitter achieves low emittance in the atmospheric window of 3–5 μm and 8–14 μm (average values of 0.32 and 0.31, respectively), and high emittance (average value of 0.73) in the non-atmospheric window of 5–8 µm, effectively reducing the infrared radiation characteristic while also considering temperature control. According to thermal imaging observation, at the heating temperature of 150 °C, the apparent radiometric temperature of the selective emitter is only 79.2 °C. The heat treatment experiment results show that the selective emitter can withstand at least two hours at 200 °C, exhibiting excellent thermal stability. In this study, the selective emitter we designed can be quickly, large-area, and low-cost prepared, providing important reference for the design of infrared selective emission materials and having broad application prospects in the field of infrared spectrum modulation.