Analysis of Physical and Electrical Properties of NiTe 2 Single Crystal Grown via Molten Salt Flux Method

Since the emergence of layered two-dimensional materials, the development of methods for their large-scale synthesis has become crucial for integrating these materials into existing fabrication processes. In this study, we report the synthesis of a NiTe 2 single crystal on the near-centimeter scale using the molten salt flux method (MSFM). The single-crystal nature of the synthesized NiTe 2 sample was confirmed using X-ray diffraction analysis, while its chemical characteristics were analyzed using X-ray photoelectron spectroscopy, which confirmed Ni–Te chemical binding. The layered structure of the ingot was confirmed using Raman spectroscopy; two prominent signals were observed, at 84 and 138 cm −1 , which were consistent with the in-plane vibrational mode, E g , and out-of-plane vibrational mode, A 1g . In addition, analyses performed on different flakes confirmed the structural uniformity of the single crystal, as only a small variation in the peak-to-peak position of the full width at half maximum was observed. Using Kelvin probe force microscopy, the electronic structure of the NiTe 2 multilayered surface was investigated to determine its surface work function, which was found to be 4.4–4.8 eV. A back-gate field-effect transistor was fabricated using the single-crystal NiTe 2 to evaluate its semimetallic characteristics; the transfer characteristic of the NiTe 2 FET, determined by applying a back-gate bias, showed weak gate voltage dependence and linear I–V characteristics, in keeping with the linear I D -V D output characteristics. Therefore, the synthesis of NiTe 2 via the MSFM should facilitate the integration of layered materials with existing fabrication processes for the mass production of electronic devices. Graphical Abstract