The irradiation damage mechanism and performance enhancement of thermochromic VO2 films under high-power laser irradiation

Vanadium dioxide (VO₂) is a phase-change material with tunable optical properties, demonstrates significant potential for smart laser protection applications. However, its practical implementation has been constrained by relatively low damage thresholds and insufficient laser irradiation resistance. This study employed atomic layer deposition (ALD) to fabricate both VO₂ and Al₂O₃/VO₂ thin films, subsequently investigating their damage mechanisms and protective performance under 1060 nm laser irradiation. Key findings reveal that ALD-prepared VO₂ films exhibit exceptional optoelectronic response characteristics, achieving 75 % infrared transmittance modulation in the 3–5 μm wavelength range accompanied by five orders of magnitude resistance variation. Nevertheless, laser-induced oxidation was identified as the primary degradation mechanism, causing up to 89.7 % deterioration in protective performance. The integration of a 10 nm Al₂O₃ protective layer not only preserved the desirable optical response properties but also reduced performance degradation to merely 6.9 % under identical irradiation conditions while extending service life by over fourfold. These results present a novel approach for developing high-threshold laser protective film.