Systematic Field Electron Emission Investigations of Vapor‐Phase‐Grown Sb2Te3 Nanosheets

Abstract

Micron‐sized Sb2Te3 nanosheets are grown on p‐type Si substrate by facile vapor‐phase route. Physicochemical properties of the Sb2Te3 nanosheets are revealed using X‐ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), transmission electron microscope (TEM), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS). Owing to their high aspect ratio, field emission (FE) characteristics of the Sb2Te3 nanosheets grown on Si substrate (termed as a “planar emitter”) are investigated. Furthermore, the FE behavior of a single Sb2Te3 nanosheet attached to a blunt tungsten needle is studied. The single nanosheet emitter exhibited superior emission behavior in contrast to the planar emitter. The Fowler–Nordheim (F–N) plot for the single nanosheet emitter exhibits linear nature, whereas for the planar emitter it shows deviation from linearity. An attempt has been made to reveal the FE properties of a single Sb2Te3 nanosheet in an “in‐plane” configuration, similar to the vacuum field emission transistor (VFET). In this case, a maximum emission current of 1 μA is observed at 290 V, which is comparable to other VFETs. The observed results clearly imply the potential of the single nanosheet emitters due to topological insulators, like Sb2Te3, for the development of new generation nanoscale vacuum electronic devices.