Nanostructured Ge/ZnS Films for Multispectral Camouflage with Low Visibility and Low Thermal Emission

Abstract

Multispectral camouflage technology against advanced detection has attracted rising attention in recent years. However, compatible camouflage with low visibility and low thermal emission in a dark background still remains challenging (such as satellites, high-altitude planes, etc.). In this work, a low visibility and low thermal emission nanostructured film with electromagnetic band gap for multispectral camouflage is proposed. The structure demonstrates a Ge/ZnS multilayer for suppressing thermal emission, which is mounted with nanolayered dielectric antireflection stacks to absorb visible light. Also, the all-dielectric configuration ensures microwave transmission for being compatible with microwave camouflage. The fabricated structure shows low reflectance (3.95%) for 300–1100 nm visible-near-IR light, low emissivity for 3–5 μm (0.043) and 8–14 μm (0.093) atmospheric window ranges, and high transmittance (98.86%) for 8–18 GHz microwave range. Moreover, the film exhibits low lightness and suppressed thermal radiation signatures with incident angles up to 60°. The proposed nanostructured Ge/ZnS film paves the way for multispectral camouflage and other applications such as solar–thermal conversion, radiation control, and optical sensing based on electromagnetic wave manipulation.