Growth, structure and stabilityof sputter-deposited MoS2 thin films
Publication from Materials
Beilstein J. Nanotechnol. 8, 1115–1126, 5/2017
Molybdenum disulphide (MoS2) thin films have received increasing interest as device-active layers in low-dimensional electronicsand also as novel catalysts in electrochemical processes such as the hydrogen evolution reaction (HER) in electrochemical watersplitting. For both types of applications, industrially scalable fabrication methods with good control over the MoS2 film propertiesare crucial. Here, we investigate scalable physical vapour deposition (PVD) of MoS2 films by magnetron sputtering. MoS2 filmswith thicknesses from ≈10 to ≈1000 nm were deposited on SiO2/Si and reticulated vitreous carbon (RVC) substrates. Samplesdeposited at room temperature (RT) and at 400 °C were compared. The deposited MoS2 was characterized by macro- and micro-scopic X-ray, electron beam and light scattering, scanning and spectroscopic methods as well as electrical device characterization.We find that room-temperature-deposited MoS2 films are amorphous, of smooth surface morphology and easily degraded uponmoderate laser-induced annealing in ambient conditions. In contrast, films deposited at 400 °C are nano-crystalline, show a nano-grained surface morphology and are comparatively stable against laser-induced degradation. Interestingly, results from electricaltransport measurements indicate an unexpected metallic-like conduction character of the studied PVD MoS2 films, independent ofdeposition temperature. Possible reasons for these unusual electrical properties of our PVD MoS2 thin films are discussed. A poten-tial application for such conductive nanostructured MoS2 films could be as catalytically active electrodes in (photo-)electrocatal-ysis and initial electrochemical measurements suggest directions for future work on our PVD MoS2 films.