Synthesis of V-Doped WTe₂ Nanolayers and Single Crystals

The discovery of 2D topological insulator in monolayer 1T’-WTe₂ indicates great potential for novel electronic, spintronic, and quantum metrology. Theoretically, the interaction between the topological states and the magnetic ordered states of Td-WTe₂ enables the modulation of Weyl semimetal states by an external magnetic field and potentially the creation of a quantum anomalous Hall phase [1-3]. However, currently, ferromagnetism in layered 1T’-WTe₂ is still not observed. We are attempting to synthesize nanolayers/ flakes of 1T’-WTe₂ with vanadium doping in order to induce magnetism. V-doped WTe₂ nanolayers/ flakes were synthesized in an atmospheric pressure CVD (APCVD) quartz tube reactor with three independent thermal zones. LP (liquid precursors) method based on ammonium metatungstate hydrate (AMT) and ammonium metavanadate (AMV) or vanadium(IV) oxide sulfate (VOSO₄) with addition of PTAS was used for the synthesis. The obtained nanolayers/clusters/flakes were studied by optical microscopy and Raman spectroscopy.<br/>In addition, we are reporting growth of V -doped WTe2 single crystals by using flux (high-temperature solution) method. Particularly the self- flux method was used for crystal growth, and tellurium was used as a solvent (flux). The grown crystals were studied by XRD, XPS and Raman spectroscopy and the typical for WTe2 X-ray diffraction patterns and Raman modes were observed. Vanadium incorporation (1.8 at. %) in the crystal structure was detected by XPS measurements. The estimated overall elemental composition in at. % confirms the presence of vanadium.<br/>Acknowledgement: We acknowledge the support of the European Union’s Horizon 2020 FET-PROACTIVE project TOCHA under grant agreement 824140.<br/>References:<br/>[1] Wu, S. et al. Science 359, 76–79 (2017)<br/>[2] Yu, R. et al. Science 329, 61–64 (2010)<br/>[3] Li, Y. et al. Adv. Funct. Mater., 31 (2021) 2008116