Vertical tellurium nano-tower arrays: Topological shape engineering to excellent field emission and optical performance

Abstract

Vertically aligned tellurium nano-towers (TNTs) building blocks comprising sharp edges have been attained by Au assisted controlled CVD method. The density, size and novel TNTs structures have been optimized in a comprehensive systematic way. The measured base diameter of the TNTs is nearly 150 nm which slowly decreases towards their tip (∼20 nm) in the form of steps realizing their sharp edges. The high density growth of TNTs is estimated to be approximately 2.5 × 108mm2. The two prominent binding energy peaks of TNTs positioned at 583.8 eV and 573.6 eV in XPS graphs are credited to Te-3d3/2 and Te-3d5/2 states of Te along with their XRD lattice parameters a = 4.14 Å and c = 5.25 Å. Owing to distinctive morphology of TNTs which is supportive to easy electron emission, have displayed incredible low turn-on value (3.15 Vμm−1 with excellent stability, exhibiting insignificant (<5 %) FE current fluctuation for 120 min. The intense photoluminescence (PL) peaks displayed by TNTs at 368 nm and comparatively weak shoulder peak at 428 nm (2.897 eV) evidences their potential application in light emitting devices (LEDs). Hence, the incredible PL properties and exclusive FE characteristics revealed by unique TNTs provides the potential applications in opto-electronics and FE display devices.