Wafer-Scale Room-Temperature Ferromagnetic Chromium Disulfide via Sulfur Monomers

The wafer-scale synthesis of magnetic two-dimensional transition metal dichalcogenides (TMDCs) remains a critical challenge due to their metastability and the rapid oxidation of metallic precursors, which block conventional sulfurization routes. Chromium disulfide (CrS₂), in particular, is highly attractive for spintronic applications because of its robust room-temperature ferromagnetism, yet its wafer-scale growth has remained elusive. Here, we report a universal strategy using ZnS-derived sulfur monomers to overcome the chemical reaction barrier imposed by native oxide layer, enabling the selective formation of crystalline CrS₂ films across 2-in. wafers. The resulting films exhibit excellent uniformity, controllable thickness, and robust ferromagnetism above room temperature. Beyond CrS₂, this method demonstrates broad application by yielding wafer-scale VS₂, MnS, FeS₂, CoS₂, and the ternary CrCoS₄ with comparable quality. Our results establish a versatile and scalable synthesis platform for 2D magnetic TMDCs, opening a pathway toward their integration in advanced spintronic devices.