Field emission behaviour of hexagonal Sb₂Te₃ micron sized platelets of nanometric thickness

Hexagonal shaped, micron sized platelets of Sb₂Te₃ having nanometric thickness were synthesized by hydrothermal route. The as-synthesized Sb₂Te₃ was characterized employing X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) to reveal its phase and morphology. The XRD analysis has confirmed the formation of crystalline phase of Sb₂Te₃, along with presence of crystalline Te phase in the synthesized product. FESEM images reveal the formation of hexagonal shaped (size ranging from 1 to 5 µm, and sub-micron thick) Sb₂Te₃ platelets. Field emission behaviour of the hexagonal shaped, micron sized platelets of Sb₂Te₃ was studied at base pressure of ∼ 1X10^-8 mbar. The values of the turn-on and threshold fields were found to be∼5.0 and 6.0 V/μm, corresponding to emission current density of 1 and 10 µA/cm², respectively. Furthermore, maximum current density of ∼ 460 µA/cm² was extracted from the emitter at an applied field 8.8 V/μm. The Sb₂Te₃ emitter exhibited fairly good emission current stability at pre-set value of 1 µA over duration of 240 minutes.