Highly efficient field emission properties of a novel layered VS2/ZnO nanocomposite and flexible VS2 nanosheet

Multi-layered VS2 nanosheets were synthesized via a facile hydrothermal process without using any additives or surfactants. Due to the large quantities of sharp edges, a VS2 nanosheet can serve as an efficient edge emitter for field emission (FE). The FE properties of VS2 nanosheets were investigated for the first time. The results indicated that the VS2 nanosheets had an excellent field emission performance with a turn-on field of ∼1.4 V μm−1 and a threshold field of ∼2.6 V μm−1 on a Si substrate. Moreover, the FE properties of ZnO-coated VS2 nanosheets were also investigated. The VS2/ZnO nanocomposite showed enhanced field emission properties with a turn-on field of ∼1.2 V μm−1 and a threshold field of ∼2.2 V μm−1, as well as an excellent emission stability without significant current degradation, which resulted from a well contacted metal–semiconductor junction and extra emission sites. In addition, the FE properties of the VS2 nanosheets were preserved on a highly flexible polyethylene terephthalate (PET) substrate. Approximately the same values of the turn-on field (∼1.8 V μm−1) and the threshold field (∼3.2 V μm−1) were measured on bent and unbent PET substrates.