Mid-Infrared Electrochromics Enabled by Intraband Modulation in Carbon Nanotube Networks

Tuneable infrared properties, such as transparency and emissivity, are highly desirable for a range of applications, including thermal windows and emissive cooling. Here, we demonstrate the use of carbon nanotube networks spray-deposited onto an ionic liquid-infused membrane to fabricate devices with electrochromic modulation in the mid-infrared spectrum, facilitat-ing control of emissivity and apparent temperature. Such modulation is enabled by intraband transitions in unsorted single-walled carbon nanotube networks, allowing the use of scalable nanotube inks for printed devices. These devices are optimized by varying film thickness and sheet resistance, demonstrating the emissivity modulation (from -,0.5 to -,0.2). These devices and the understanding thereof open the door to selection criteria for infrared electrochromic materials based on the relationship between band structure, electrochemistry, and optothermal properties to enable the development of solution-processable large-area coatings for widespread thermal management applications.

Automated summary

Tunable infrared properties are achieved with carbon nanotube networks spray-deposited onto an ionic liquid-infused membrane, allowing for control of emissivity and apparent temperature. These devices utilize intraband transitions in carbon nanotube networks to enable scalable and printed devices, resulting in emissivity modulation from -0.5 to -0.2. The understanding of these devices provides criteria for infrared electrochromic materials, opening the possibility for solution-processable coatings in thermal management applications.