Two-Dimensional Metallic Vanadium Ditelluride as a High-Performance Electrode Material

Two-dimensional (21)) metallic transition-metal dichalcogenides (MTMDCs) are considered as ideal electrode materials for enhancing the device performances of 21) semiconducting transition-metal dichalcogenides, due to their similar atomic structures and complementary electronic properties. Vanadium ditelluride (VTe2) behaves as a fascinating material in MTMDCs family, presenting room-temperature ferromagnetism, charge density waves order, and topological property. However, its practical applications in universal electrode/energy-related fields remain unexplored. Herein, we achieved the direct synthesis of ultrathin, large-domain, and thickness-tunable 1T-VTe2 nanosheets on an easily available mica substrate by chemical vapor deposition (CVD). We further uncover that the CVD-derived 1T-VTe2 can serve as a high-performance electrode material thanks to its ultrahigh conductivity. Accordingly, a 6 times higher field-effect mobility (similar to 47.5 cm(2) V-1 s(-)(1)) was achieved in 1T-VTe2-contacted monolayer MoS2 devices than that using a conventional Ti/Au electrode (similar to 8.1 cm(2) V-1 s(-)(1)). Moreover, the CVD-synthesized 1T-VTe2 nanosheets are revealed to present excellent electrocatalytic activity for hydrogen evolution reaction. These results should propel the direct application of CVD-grown 2D MTMDCs as high-performance electrode materials in all 2D materials related devices.

Automated summary

In this study, ultrathin, large-domain, and thickness-tunable 1T-VTe2 nanosheets were successfully synthesized on an easily available mica substrate by chemical vapor deposition (CVD). These CVD-derived 1T-VTe2 nanosheets show excellent electrocatalytic activity and high conductivity, making them promising electrode materials with potential applications in various devices. Compared to conventional Ti/Au electrodes, devices using 1T-VTe2 contacted monolayer MoS2 achieved significantly higher field-effect mobility.