Atomically thin Mo_1−xW_xS₂ (0 ≤ x ≤ 1) ternary compounds have been grown on 2-inch c-plane sapphire substrates with high uniformity by sulfurizing thin Mo_1−xW_x layers that were deposited at room temperature using a co-sputtering technique. Atomic force microscopy (AFM), Raman scattering, and optical absorbance spectroscopy (OAS) studies reveal that the Mo_1−xW_xS₂ films consist of crystallites of two-to-four monolayers in thickness. X-ray photoelectron spectroscopy (XPS) shows that the core levels of Mo3d and W4f shift to lower binding energies while that of S2p shifts to higher ones with the increase in W compositions, which can be related to the larger electron affinity of W (0.8163 eV) than that of Mo (0.7473 eV). OAS has also shown that the direct bandgap of Mo_1−xW_xS₂ is tuned from 1.85 to 1.99 eV by increasing x from 0 to 1. Both E¹ _2g and A_1g phonon modes of the Mo_1−xW_xS₂ films exhibit a two-mode behavior. The bandgap tuning and the two-mode phonon behaviors are typically the same as those recently observed in monolayer Mo_1−xW_xS₂ obtained by mechanical exfoliation, thus shedding light on the bottom-up growth of large-scale two-dimensional Mo_1−xW_xS₂ ternary alloys.

High entropy alloys (HEAs), consisting of five or more elements with nearly equal atomic composition with one another (5–35%), are new-generation alloys that have attracted significant interest since their advent in 2004 because of their unique structural and mechanical properties and thermodynamic and chemical stability. Some characteristics, including high mechanical strength at elevated temperatures, high ductility and fracture toughness at cryogenic temperatures and high corrosion, erosion and wear resistance, have been demonstrated for HEAs that outperform traditional alloys and superalloys. Laser-cladding (LC) is an additive manufacturing technique that has good feasibility in designing and processing HEAs for advanced structural components and protective coatings. This overview provides a glimpse of recent advances in LC of HEAs in terms of design fundamentals, metallurgical phase and microstructure, specific properties for advanced coating applications and the effect of ceramic particles reinforcement in LC deposition of HEA coatings.