A solution-processed radiative cooling glass.

Passive daytime radiative cooling materials could reduce the energy needed for building cooling up to 60% by reflecting sunlight and emitting long-wave infrared (LWIR) radiation into the cold Universe (~3 kelvin). However, developing passive cooling structures that are both practical to manufacture and apply while also displaying long-term environmental stability is challenging. We developed a randomized photonic composite consisting of a microporous glass framework that features selective LWIR emission along with relatively high solar reflectance and aluminum oxide particles that strongly scatter sunlight and prevent densification of the porous structure during manufacturing.

Dynamically switchable self-focused thermal emission.

The ability to manipulate thermal emission is paramount to the advancement of a wide variety of fields such as thermal management, sensing and thermophotovoltaics. In this work, we propose a microphotonic lens for achieving temperature-switchable self-focused thermal emission. By utilizing the coupling between isotropic localized resonators and the phase change properties of VO, we design a lens that selectively emits focused radiation at a wavelength of 4 µm when operated above the phase transition temperature of VO.

Enabling Manufacturable Optical Broadband Angular-Range Selective Films.

The ability to control the propagation direction of light has long been a scientific goal. However, the fabrication of large-scale optical angular-range selective films is still a challenge. This paper presents a polymer-enabled large-scale fabrication method for broadband angular-range selective films that perform over the entire visible spectrum.

Vapor condensation with daytime radiative cooling.

A radiative vapor condenser sheds heat in the form of infrared radiation and cools itself to below the ambient air temperature to produce liquid water from vapor. This effect has been known for centuries, and is exploited by some insects to survive in dry deserts. Humans have also been using radiative condensation for dew collection.

Thermal camouflage based on the phase-changing material GST.

Camouflage technology has attracted growing interest for many thermal applications. Previous experimental demonstrations of thermal camouflage technology have not adequately explored the ability to continuously camouflage objects either at varying background temperatures or for wide observation angles. In this study, a thermal camouflage device incorporating the phase-changing material GeSbTe (GST) is experimentally demonstrated.

Active control of anapole states by structuring the phase-change alloy GeSbTe.

High-index dielectric nanoparticles supporting a distinct series of Mie resonances have enabled a new class of optical antennas with unprecedented functionalities. The great wealth of multipolar responses has not only brought in new physical insight but also spurred practical applications. However, how to make such a colorful resonance palette actively tunable is still elusive.

Nonvolatile tunable silicon-carbide-based midinfrared thermal emitter enabled by phase-changing materials.

Polar crystals can enable strong light-matter interaction at an infrared regime and provide many practical applications including thermal emission. However, the dynamic control of thermal emission based on polar crystals remains elusive as the lattice vibrations are solely determined by the crystal structure. Here, a nonvolatile tunable midinfrared thermal emitter enabled by a phase-changing film GeSbTe on silicon carbide polar crystal is demonstrated.

Tunable dual-band thermal emitter consisting of single-sized phase-changing GST nanodisks.

Thermal emission control has been attracting increased attention in both fundamental science and many applications including infrared sensing, radiative cooling and thermophotovoltaics. In this paper, a tunable dual-band thermal emitter including phase-changing material Ge2Sb2Te5 (GST) is experimentally demonstrated. Two emission peak wavelengths are at 7.

Wavelength-tunable mid-infrared thermal emitters with a non-volatile phase changing material.

The ability to continuously tune the emission wavelength of mid-infrared thermal emitters while maintaining high peak emissivity remains a challenge. By incorporating the nonvolatile phase changing material GeSbTe (GST), two different kinds of wavelength-tunable mid-infrared thermal emitters based on simple layered structures (GST-Al bilayer and Cr-GST-Au trilayer) are demonstrated. Aiming at high peak emissivity at a tunable wavelength, an Al film and an ultrathin (∼5 nm) top Cr film are adopted for these two structures, respectively.