AI Insight
Researchers developed solid-state nanophotonic thermal emitters based on chalcogenide phase-change materials, designed with neural-network-guided photonic optimization, capable of adaptively switching thermal infrared emissivity with high spectral contrast across a broad spectrum spanning solar to thermal infrared wavelengths. The emitters maintain low solar absorptivity while enabling switchable thermal emission, and were experimentally tested in a stratospheric environment simulating space-like radiative conditions, where a temperature differential of 31.5 degrees Celsius was observed between the two solid-state phases of a GeSbTe-225 emitter. Theoretical projections suggest the system could modulate more than 600 W/m2 of radiative heat at 100 degrees Celsius in the vacuum of space, with no power required to maintain either state.
Why it matters
This technology could significantly advance passive and adaptive thermal management for satellites, spacecraft, and future planetary habitats, as well as terrestrial applications such as radiative cooling of buildings and vehicles, without relying on moving parts or continuous power consumption.
arXiv:2605.21619v1 Announce Type: new
Abstract: Managing the emission and absorption of thermal radiation is crucial for a wide range of technologies, from radiative cooling of buildings and vehicles to thermal regulation of satellites and future lunar and Mars habitats. Despite this universal and critical need, thermal emitters capable of adaptively modulating emissivity in a broadband, high-contrast, and fully solid-state manner remain elusive. Here, we leverage neural-network-guided photonic design to enable adaptive, solid-state thermal emitters based on chalcogenide phase-change materials capable of emissivity switching with extreme spectral contrast and bandwidth. These engineered nanophotonic emitters operate over a broad spectrum$-$from solar through thermal infrared$-$providing very low solar absorptivity while enabling switchable thermal infrared emissivity with high contrast. We experimentally demonstrate the core functionality of our approach in the space-like radiative environment in the stratosphere, observing a 31.5 {deg}C temperature differential between the two solid-state phases of a simplified chalcogenide GeSbTe-225 thermal emitter. Our results point to even more significant capabilities, such as the potential to modulate >600 W/m$^2$ of radiative heat (at 100 {deg}C) with minimal solar heating in the vacuum of space. The proposed nanophotonic solid-state adaptive emitter could provide high-power and high-speed heat modulation while requiring no power to maintain state, offering transformative capabilities for thermal control in dynamic radiative environments on Earth and in space.
Source: Adaptive and ultrabroadband thermal control with solid-state nanophotonic emitters