Electronic‐State Regulation Enables Robust Infrared Camouflage at Extreme Temperatures

ABSTRACT Stable suppression of midwave infrared (MWIR, 3–5 µm) thermal emissivity at elevated temperatures is critical for advanced thermal camouflage applications. However, most infrared camouflage systems suffer from rapid emissivity rebound at high temperatures due to oxidative degradation, microstructural instability, or enhanced phonon‐mediated radiation. Herein, a vacancy‐associated electronic‐state regulation strategy is developed to achieve robust low MWIR emissivity in perovskite SrZrO 3 . Electronic‐state regulation modifies the MWIR optical response by modulating defect and carrier states while maintaining low infrared absorption. For optimized Co‐doped SrZr 1− x Co x O 3‐ δ (SZCO), DFT calculations yield an electronic gap of approximately 0.51 eV, accompanied by oxygen‐vacancy formation and a 67% increase in carrier concentration. Consequently, the optimized SZCO‐3 sample exhibits an ultralow MWIR emissivity of 0.296 at room temperature and retains a low value of 0.394 even at 1100°C. High‐temperature in situ characterizations and durability tests confirm the excellent thermal robustness of SZCO‐3. Meanwhile, thermally activated charge transport and structural symmetry evolution contribute to maintaining its stable MWIR response at elevated temperatures. These findings establish vacancy‐associated electronic‐state regulation as an effective strategy for designing thermally robust, low‐emissivity ceramics for high‐temperature infrared camouflage applications.