Large-area uniform few-layer PtS2: Synthesis, structure and physical properties

At present, the research in field of the transition metal dichalcogenides (TMDs) was mostly concentrated in the group 6 TMDs such as MoS 2 and WS 2 for numerous applications like optoelectronics , sensing and so on. However, our research focuses on the group 10 of TMDs, which is relatively unexplored. Platinum disulfide (PtS 2 ), a typical representative of the group 10 TMDs, is a newly developed two-dimensional materials with high carrier mobility , widely tunable bandgap, and ambient stability for electronic and optoelectronic applications. Here, we experimentally and theoretically investigate the synthesis, structure and physical properties of the few-layer PtS 2 . A inch scale of few-layer PtS 2 was synthesized by direct sulfurization of Pt metal sputtered on the SiO 2 /Si substrate in a Plasma Enhanced Chemical Vapor Deposition (PE-CVD) furnace. And the electronic band structure of layered PtS 2 was obtained by density function theory (DFT). A series of characterizations including Raman spectroscopy , Photoluminescence (PL), atomic force microscopy (AFM), scanning electron microscope (SEM), high-resolution transmission electron microscope (HR-TEM) and X-ray photoelectron spectroscopy (XPS) have demonstrate the quality and uniformity of the few-layer PtS 2 as prepared. Moreover, the field-effect transistor (FET) was fabricated based on PtS 2 in order to investigate their electronic properties, which show a p-type semiconductor behavior. Further, the work function and potential difference of the PtS 2 on the SiO 2 /Si substrate were measured by Kelvin probe force microscopy (KPFM), showing 32 meV and 36 mV, respectively. The few-layer PtS 2 samples were treated with oxygen plasma to investigate the Raman transforms, exhibiting the reduction of Raman intensity after treatment due to oxidation . The idea that this synthesis strategy can also be applied to other PtX 2 devices are speculated to promote the application of TMDs in advanced optoelectronic devices.