Large-area sputtered 2H-MoS2 thin films for spin and orbital charge conversion

Abstract We report the growth and characterization of large-area molybdenum disulfide (MoS₂) thin films synthesized by RF magnetron sputtering followed by in situ high-vacuum annealing. Structural stabilization of the semiconducting 2H phase was achieved via post-deposition annealing, as confirmed by Raman spectroscopy, X-ray diffraction, and electron microscopy. Atomic force microscopy and X-ray reflectivity revealed smooth surfaces and sharp interfaces, while energy-dispersive spectroscopy confirmed uniform stoichiometry without interfacial diffusion. Scanning tunneling spectroscopy demonstrated semiconducting behavior, with a tunable bandgap, consistent with the 2H structural phase, interlayer coupling and quantum confinement. These results establish sputtering with optimized annealing as a reliable route to large-area, phase-pure MoS₂ with tunable properties. Building on this structurally robust platform, we investigated angular momentum transport using spin pumping via ferromagnetic resonance. Pronounced signals were observed in MoS₂/Py(Ni₈₁Fe₁₉) bilayers, which are comparable to those of Pt/Py. To enhance orbital current pumping, we fabricated MoS₂/Pt/Py heterostructures, where the signal magnitude differs strongly from Pt/Py and remains independent of MoS₂ thickness. This behavior highlights a dominant interfacial contribution to spin–orbital–charge conversion, positioning MoS₂ films as promising platforms for spin–orbitronics.