Structural and Infrared Spectral Modulation Properties of a CuNiAg Alloy/Ni—Ag-Doped Cu₄O₃ One-Dimensional Photonic Crystal

To develop a new material with low emissivity in the range of the 3–5 μm band, the present work reports a CuNiAg alloy/Ni—Ag-doped Cu4O3 one-dimensional photonic crystal prepared by reactive sputtering and correlates the effect of nickel and silver on the structural and infrared spectral properties. The morphology, structure and infrared spectral properties of the CuNiAg alloy/Ni—Ag-doped Cu4O3 1DPC were studied by FESEM, XRD, and an IR-2 dual-wavelength emissivity instrument. The doping of Ni and Ag impeded phase formation, and the Cu2O and Cu4O3 phases only appeared under the same process conditions. The doped elements caused lattice contraction and decreased the thickness of the 1DPC, which was the most important factor affecting the emissivity. The results of the emissivity measurement showed that the single period film thickness of Cu80Ni15Ag5/Ni-Ag-doped Cu4O3 was close to 280 nm, and the number of periods was 2–4. Therefore, the Cu80Ni15Ag5/Ni-Ag-doped Cu4O3 1DPC had good selective infrared properties with an average emissivity of less than 0.1 in the 3–5 μm band and larger than 0.94 in the 8–14 μm band; thus, this 1DPC is expected to be used as an infrared spectral modulation material.