Related papers: Wavelength-selective thermal nonreciprocity barely…
The Kirchhoff`s law of thermal radiation stating the equivalence of emissivity and absorptivity at the same wavelength, angle, and polarization, has completely constrained emission and absorption processes. Achieving strong nonreciprocal…
Kirchhoff's law of thermal radiation, which dictates that the emissivity of a surface equals its absorptivity under thermal equilibrium, which dictates that the emissivity of a surface equals its absorptivity under thermal equilibrium,…
Nonreciprocal thermal emitters that break the conventional Kirchhoff's law allow independent control of emissivity and absorptivity and promise exciting new functionalities in controlling heat flow for thermal and energy applications. In…
Thermal radiation is strictly governed by Kirchhoff s law to reach thermal equilibrium. The violation of Kirchhoff s law decouples nonreciprocally the equity between absorptivity and emissivity, enabling exotic thermal engineering…
Can thermal nonreciprocity improve the radiative cooling efficiency? Probably not.
Breaking Kirchhoff's law of thermal radiation yields new opportunities in one-way radiative thermal transport and circuitry. We investigate its consequences in the far-field regime in cylindrical cavities, by employing a specular…
To violate Kirchhoff s law is very important in the areas of thermal radiation. However, due to the weak nonreciprocity in natural materials, it is necessary to engineer novel structures to break the balance between emission and absorption.…
Solid-state cooling via electroluminescent emission from light-emitting diodes is a promising alternative to thermoelectric and vapor-compression refrigeration, but practical performance remains limited by nonradiative losses and…
The climate impact of building envelopes is often quantified using their energy savings and CO2 emission reduction benefits. However, building envelopes also trap solar and thermal infrared heat, which is dissipated as a direct heating…
Nonreciprocal thermal emitters that break Kirchhoff's law of thermal radiation promise exciting applications for thermal and energy applications. The design of the bandwidth and angular range of the nonreciprocal effect, which directly…
Radiative coolers that can passively cool objects by radiating heat into the outer space have recently received much attention. However, the ultimate limits of their performance as well as their ideal spectral design are still unknown. We…
Recent advancements in nonreciprocal thermal emitters challenge the conventional Kirchhoff's law, which states that emissivity and absorptivity should be equal for a given direction, frequency, and polarization. These emitters can break…
Passive radiative cooling involves a net radiative heat loss into the cold outer space through the atmospheric transmission windows. Due to its passive nature and net cooling effect, it is a promising alternative or complement to electrical…
A fundamental limit of current radiative cooling systems is that only the top surface facing deep-space can provide the radiative cooling effect, while the bottom surface cannot. Here, we propose and experimentally demonstrate a concept of…
Spectral/angular emissivity $e$ and absorptivity ${\alpha}$ of an object are widely believed to be identical by Kirchhoff's law of thermal radiation in reciprocal systems, but this introduces an intrinsic and inevitable energy loss for…
Infrared (IR)-transparent passive radiative cooling (PRC) enables non-contact thermal management by regulating radiative heat exchange without direct attachment to the cooling object. While asymmetric IR transmission at a specific incidence…
Radiative cooling, taking advantage of the coldness of the sky, has a potential to be a sustainable alternative to meet cooling needs. The performance of a radiative cooling device is fundamentally limited by the emissivity of the sky,…
In this work we solve approximately the radiative heat transfer problem in one dimension to perform a comparative analysis of the time averaged performance of the partially transparent radiative windows and radiative coolers. Our physical…
Kirchhoff's law of thermal radiation imposes a constraint on photon-based energy harvesting processes since part of the incident energy flux is inevitably emitted back to the source. By breaking the reciprocity of the system, it is possible…
Passive radiative cooling drawing the heat energy of objects to the cold outer space through the atmospheric transparent window (8 um - 13 um) is significant for reducing the energy consumption of buildings. Daytime and nighttime radiative…