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

Abstract

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.