The growth mechanism of PtS2 single crystal.

PtS2, a member of the group 10 transition metal dichalcogenides (TMDs), has received extensive attention because of its excellent electrical properties and air stability. However, there are few reports on the preparation of single-crystal PtS2 in the literature, and the growth mechanism of single crystal PtS2 is not well elucidated. In this work, we proposed a method of preparation that combines magnetron sputtering and chemical vapor transport to obtain monocrystalline PtS2 on a SiO2/Si substrate. By controlling the growth temperature and time, we have synthesized a single crystalline PtS2 of hexagonal shape and size of 1-2 µm on a silicon substrate. Combining the molecular dynamics simulation, the growth mechanism of single crystal PtS2 was investigated both experimentally and theoretically. The synthesis method has a short production cycle and low cost, which opens the door for the fabrication of other TMDs single crystals.

Centimeter-Scale Few-Layer PdS2: Fabrication and Physical Properties.

To develop next-generation electronic devices, novel semiconductive materials are urgently required. The transition metal dichalcogenides (TMDs) hold the promise of next generation of semiconductor materials for emerging electronic applications. As a member of the group-10 TMDs, PdS2 has a notable layer-number-dependent band structure and tremendously high carrier mobility at room temperature. Here, we demonstrate the experimental realization of centimeter-scale synthesis of the few-layer PdS2 by the combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods. For the first time, the optical anisotropic properties of the few-layer PdS2 were investigated through angle-resolved polarized Raman spectroscopy. Also, the evolution of Raman spectra was studied depending on the temperature in the range of 12-300 K. To further understand the electronic properties of the few-layer PdS2, the field-effect transistor (FET) devices were fabricated and investigated. The electronic measurements of such FET devices reveal that the PdS2 materials exhibit a tunable ambipolar transport mechanism with field-effect mobility of up to ∼388 cm2 V-1 s-1 and the on/off ratio of ∼800, which were not reported before in the literature. To well understand the experimental results, the electronic structure of PdS2 was determined using density functional theory (DFT) calculations. These excellent physical properties are very helpful in developing high-performance opto-electronic applications.