M/MoS2 (M = Ti, Al, Mo, Ag) Nanofilms: Preparation by Magnetron Sputtering and Effects of Power of Magnetron Sputtering and Medium/Low-Temperature Annealing

Molybdenum disulfide (MoS₂) has been widely applied in photocatalysts, field-effect transistors (FETs), and solar cells in virtue of its high specific surface area and superior carrier mobility. Nevertheless, conventional MoS₂-based FETs involve Au and Ag as the electrode materials, resulting in a high manufacturing cost. More importantly, conventional preparation methods (e.g., chemical vapor deposition) require a high-temperature process and transfer of MoS₂, as well as subsequent electrode deposition, for device fabrication, while transfer of MoS₂ tends to cause secondary contamination. In this study, M/MoS₂ (M = Al, Ti, Mo, Ag) nanofilms were prepared by magnetron sputtering at room temperature. Herein, cost-effective electrode metals were used as the electrodes, and the transfer of MoS₂ is avoided. Meanwhile, the effects of key factors, including the power of magnetron sputtering and postsputtering annealing, on the electrical performance of as-prepared M/MoS₂ nanofilms were explored. The results demonstrated that the power of magnetron sputtering and medium- and low-temperature annealing significantly affected film morphology (e.g., particle size and surface roughness) and structure (e.g., crystallinity and structural integrity). Specifically, the resistivities of metal-semiconductor contacts of M/MoS₂ increased and then decreased as the power of magnetron sputtering increased; medium/low-temperature annealing led to decreased electrical resistivity at the metal-semiconductor contact of M/MoS₂. Additionally, the M metal had a significant influence on the electrical performance of M/MoS₂. Among the as-prepared composites, Mo/MoS₂ exhibited the lowest contact resistance, making Mo most suitable for the electrode in MoS₂-based electronic devices. This study provides insights for the preparation of large-area M/MoS₂ nanofilms with improved electrical performances by cost-effective magnetron sputtering.