Fig. 1. (a) Schematic of an infrared thermal camouflage scenario. (b) Perspective view and (c) cross-sectional view of electrically controlled dynamic infrared thermal camouflage structures based on GST. The metasurface consists of an Au pillar array, a GST layer, a Pt layer, a SiO2 layer, and a Si substrate. (d) Permittivities of GST across the visible to infrared wavebands.

Fig. 2. Simulated emissivity spectra of the MIM thermal emitters at different crystallization fractions of GST. The higher the crystallization fraction of GST, the larger the permittivity and refractive index of GST, resulting in a redshift of plasmonic resonant peaks.

Fig. 3. Magnetic field intensity components |Hy| in x−z plane. (a)–(c) correspond to the results of aGST-emitter at peak wavelengths of 3.7 μm, 4.3 μm, and 10.6 μm. (d) and (e) correspond to the results of the cGST-emitter at peak wavelengths of 3.6 μm and 5.5 μm.

Fig. 4. GCA simulations of the quench-rate-dependent amorphization in GST. (a) Evolution of the temperature and the Xf for four constant quench rates. Temperature range for recrystallization is depicted with a gray rectangle. (b) Simulation snapshots of the GST film after quenching at different rates. Lower quench rates result in more and larger crystalline clusters (see https://doi.org/10.6084/m9.figshare.24502888Visualization 1https://doi.org/10.6084/m9.figshare.24502879https://doi.org/10.6084/m9.figshare.24502882–https://doi.org/10.6084/m9.figshare.24502885Visualization 4). (c) Crystalline fraction as a function of the quench rate.

Fig. 5. Simulated temperature characteristics of the GST-based thermal emitter. (a) Temperature variation curves of GST at different locations with pulse durations of 100 ns and 400 ns. (b) Maximum temperature map at GST top surface under excitation pulses with different pulse durations and voltages. The white line represents the isothermal line at 640°C. (c) Temperature distributions along z-direction for different pulse duration and voltage combinations. The purple area represents the GST film. (d) Temperature variation curves of the GST top surface after the end of the electrical pulses. The gray area represents the re-crystallization range where the molten GST is prone to recrystallization. (e) Temperature distributions at the GST bottom surface and (f) top surface.

Fig. 6. Radiant intensity of the GST-based emitter at different temperatures and crystallization fractions and dynamic thermal camouflage performance under (a) vegetation and (b) iron background. The background temperature map of (c) vegetation and (d) iron where thermal camouflage can be obtained for the emitter with different actual temperatures and crystallization fractions.