Open Access

ARTICLE

In₃SbTe₂-Based Wideband Radiator with Gradient Emittance and Low Solar Absorptance

Yang Long¹, Bowei Xie^2,*, Linkang Wang¹, Mu Du^2,*
1 Department of Mechanical and Electrical Engineering, Jiangxi Water Resources Institute, Nanchang, China
2 Institute for Advanced Technology, Shandong University, Jinan, China
* Corresponding Author: Bowei Xie. Email: " />, ; Mu Du. Email: " />

Frontiers in Heat and Mass Transfer https://doi.org/10.32604/fhmt.2026.082479

Received 17 March 2026; Accepted 26 May 2026; Published online 03 July 2026

Abstract

This work proposes a simple multilayer smart coating with wide-band response characteristics based on In₃SbTe₂ (IST) phase change material, which can achieve significant and gradient dynamic regulation of infrared emittance while ensuring a low solar absorptance. The spectral directional emittance and absorptance characteristics are calculated by the rigorous coupled wave analysis method, and the genetic algorithm is used for global optimization design of the structural parameters. The simulated results show that the smart coating can maintain excellent optical performance with a solar absorptance lower than 0.325, while achieving a significant regulation range of infrared emittance over 0.80. This excellent radiation characteristic is primarily attributable to the interference effect of the FP resonant cavity and the multiple reflection mechanism of the multilayer film structure. The smart coating has been demonstrated to retain its the low solar absorptance and significant regulation of infrared emittance under different polarization states and large incident angles. Through the regulation of crystallinity parameters within the IST phase-change layer, continuous and stepwise modulation of thermal emittance can be realized, which markedly improves the dimension and flexibility of radiative property control. A quantitative analysis of the intelligent coating reveals that it possesses excellent radiation heat flow regulation capability. Its net radiation heat flux density can be dynamically adjusted from −400 to 600 W/m² within the temperature range of 250 to 330 K. Benefiting from its outstanding radiative properties and tunable regulation performance, the proposed smart coating exhibits promising application potentials in intelligent building energy conservation systems and aerospace thermal control fields, thereby laying a solid theoretical foundation for the development of novel intelligent thermal management technologies.

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Keywords

Smart coating; IST; gradient emittance; FP resonance; multiple reflection

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