Chemical vapor deposition and temperature-dependent Raman characterization of two-dimensional vanadium ditelluride.

Recently, ultrathin two-dimensional (2D) metallic vanadium dichalcogenides have attracted widespread attention because of the charge density wave (CDW) phase transition and possible ferromagnetism. Herein, we report the synthesis and temperature-dependent Raman characterization of the 2D vanadium ditelluride (VTe 2 ). The synthesis is done by atmospheric pressure chemical vapor deposition (APCVD) using vanadium chloride (VCl 3 ) precursor on fluorphlogopite mica, sapphire, and h-BN substrates. A large area of the thin film with thickness ∼10 nm is grown on the hexagonal boron nitride (h-BN) substrate. Temperature-dependent Raman characterization of VTe 2 is conducted from room temperature to 513 K. Remarkable changes of Raman modes at around 413 K are observed, indicating the structural phase transition.