Cathodic Cage Plasma Deposition of Nanostructured Cu–Fe–Se Coatings on Poly(methyl Methacrylate)

In this research work, nanostructured Cu–Fe–Se‐based coatings were deposited on poly(methyl methacrylate) (PMMA) substrates using a modified cathodic cage plasma deposition system equipped with composite material rings. Samples were placed outside the cathodic cage to avoid thermal degradation of the polymer substrate. The influence of the cathodic cage temperature (150°C–250°C) was examined, as it affects sputtering and deposition on the PMMA substrate. X‐ray diffraction analysis of the sintered composite rings confirmed the target structure prior to deposition. Scanning electron microscope and energy‐dispersive X‐ray spectroscopy showed that, with increasing temperature, a transition occurred from a discontinuous selenium‐rich coating at 150°C to a compact and homogeneous nanostructured film at 200°C with higher copper and iron content. At 250°C, it changed to a ripple‐textured morphology with higher metallic incorporation and reduced selenium content. Optical analysis revealed temperature‐dependent changes in reflectance behavior and apparent band gap. Electrical measurements showed a minimum sheet resistance of 7.29 kΩ/sq at 200°C, indicative of CuFeSe 2 ‐type phase. X‐ray photoelectron spectroscopy showed temperature‐dependent modification of Cu, Fe, and Se chemical states and improved Cu–Se bonding at 200°C. The results show a correlation between cathodic cage temperature and structural–electronic properties of Cu–Fe–Se coatings.