Laser-Induced Tuning and Spatial Control of the Emissivity of Phase-Changing Ge2Sb2Te5 Emitter for Thermal Camouflage

Chanhee Kim, Yeongseon Kim, Myeongkyu Lee

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

The tuning of a material's emissivity in the atmospheric window range of 8–13 µm is crucial for infrared (IR) adaptive applications such as thermal camouflage, IR stealth, and radiative cooling. A resonator structure comprising a phase-changing Ge2Sb2Te5 (GST) film on a metal mirror is promising as a tunable thermal emitter because its long-wavelength IR emissivity can be varied by adjusting the degree of crystallization of the GST film through annealing. However, the space-selective tuning of the emissivity required for practical use remains a significant challenge. Herein, a hybrid method combining laser irradiation and heat treatment is presented for space-selective and continuous tuning of the emissivity of a GST-based resonator. The current study shows that a laser-induced crystalline layer formed in the near-surface region of a 400 nm thick amorphous GST film can act as heterogeneous nuclei for crystallization when the film is subsequently annealed, thereby increasing the crystallization rate of the GST film. This results in a large difference in emissivity between the irradiated and nonirradiated areas, and the emissivity difference can be tuned by changing the annealing temperature. Thermal camouflage is experimentally demonstrated by making high-and low-temperature regions with low and high emissivity, respectively.

Original languageEnglish
Article number2101349
JournalAdvanced Materials Technologies
Volume7
Issue number8
DOIs
Publication statusPublished - 2022 Aug

Bibliographical note

Publisher Copyright:
© 2022 Wiley-VCH GmbH.

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Mechanics of Materials
  • Industrial and Manufacturing Engineering

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