Structural, Microstructural, and Physical Properties of Pb x Cd 1‐x S Thick Films Prepared by Flux‐Assisted Screen Printing: A Comprehensive Review

Lead cadmium sulfide (Pb x Cd 1‐x S) thick films have established themselves as a technologically significant and cost‐effective material platform for mid‐ to long‐wavelength infrared (MWIR/LWIR) detection. This review provides a comprehensive and critically integrated examination of their development, with particular emphasis on flux‐assisted screen printing as the fabrication route that uniquely combines compositional tunability, processing scalability, and economic viability for large‐area (>100 cm 2 ) film deposition exceeding 5 µm in thickness. Flux‐assisted screen printing uniquely combines compositional tunability, scalability, and cost‐effectiveness, positioning Pb x Cd 1‐x S thick films as a technologically competitive infrared material system. Critical properties including tunable band gap (0.4–1.8 eV), high carrier mobility (50–200 cm 2 /V·s), and moderate cooling requirements are analyzed in relation to composition Pb x Cd 1‐x S, microstructure, and processing parameters. While traditional applications span thermal imaging, spectroscopy, and remote sensing, emerging uses in flexible wearables, thermoelectric (ZT > 0.5), neuromorphic vision sensors, multi‐junction photovoltaic architectures and tandem photovoltaics are highlighted. Current challenges include 1/f noise, compositional homogeneity, Pb toxicity, and large‐area uniformity. Future scope emphasizes lead‐reduction strategies, core–shell architectures, Sb 2 Se 3 hybrids and multi‐functional heterojunction integration applications. The advancements in deposition control and defect engineering position Pb x Cd 1‐x S thick films for next‐generation, affordable IR technologies.