Promising field electron emission performance of vertically aligned one dimensional (1D) brookite (β) TiO₂nanorods

Abstract

We evidence field-electron emission (FE) studies on the large-area array of one-dimensional (1D) brookite (b) TiO 2 nanorods. The pure 1D b-TiO 2 nanorods of 10 nm width and 760 nm long were synthesized on Si substrate utilizing hot-filament metal vapor deposition technique. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis evidenced the b-TiO 2 nanorods to be composed of orthorhombic crystals in brookite (b) phase. X-ray photoemission spectroscopy (XPS) revealed the formation of pure stoichiometric (i.e. 1 : 1.98) 1D TiO 2 nanorods. The values of turn-on field, required to draw current density of 10 mA cm À2 , was observed 3.9 V mm À1 for pristine 1D b-TiO 2 nanorods emitters, which were found significantly lower than doped/undoped 1D TiO 2 nanostructures (i.e. nanotubes, nanowires, nanorods) based field emitters. The enhanced FE behavior of the TiO 2 /Si emitter can be attributed to modulation of electronic properties due to the high aspect ratio of vertically aligned TiO 2 nanorods. Furthermore, the orthodox emission situation of pristine TiO 2 /Si emitters exhibit good emission stability and reveal their potentials as promising FE material.

An Investigation on the Effect of Li–Ion Cycling on the Vertically Aligned Brookite TiO2 Nanostructure

“…The lower BE peak located at 530.5 eV corresponds to O (1 s) core level of O 2− anions in 1D β‐ TiO 2 nanorods. It confirms the Ti–O chemical bonding (O 1s Ti− °) in TiO 2 nanorods . The higher BE peak at 531.9 eV is attributed to surface contaminations of as‐synthesized nanorods by carbon oxides or hydroxides, etc .…”

“…In this paper, we report on the utilization of 1D β ‐TiO 2 nanorods arrays as promising anode material for Li‐ion batteries. The large area arrays of vertically aligned TiO 2 nanorods of brookite phase were synthesized using the hot‐filament metal vapor deposition (HFMVD) technique, which is a unique and simple technique to provide diverse nanostructures morphologies . The structural morphology and chemical composition, electronic structure and chemical state of as‐synthesized large‐area arrays β –TiO 2 nanorods were examined utilizing X‐ray photoemission spectroscopy (XPS), field‐emission scanning electron microscopy (FESEM), and Raman Spectroscopy.…”

Controlled Hetero‐Architectures of Au‐Nanoparticles‐Decorated ZnO Nanowires for Enhanced Field Electron Emission Displays

“…Especially, decoration of Au nanoparticles for 24 hr along the textural boundaries of ZnO nanowires yields a larger emission current density of 2.1 mA/cm 2 at a lower applied field of 1.92 V/μm. Moreover, emission current density (i. e., 2.1 mA/cm 2 ) achieved from Au@ZnO nanowires (≡ Au/ZnO/ITO) at lower applied field (i. e., 1.92 V/μm) is relatively higher than the values reported for Ag/GO/ZnO composites, CNT‐ZnO composites, ZnO nanowire/CNT heterojunction, pristine ZnO nanopillers, metal particle decorated ZnO nanorods, Au decorated ZnO nanowires/nanopillers,, and CuO nanoplates, and pristine and MoS 2 decorated β ‐TiO 2 ranorods ,. The E on of ZnO/ITO (i. e., E on = 1.56 V/μm) required to acquire current density of 10 μA/cm 2 is reduced considerably after the controlled decoration of various amounts of Au nanoparticles.…”

Spitzer shaped ZnO nanostructures for enhancement of field electron emission behaviors

“…[6][7][8][9] Therefore, emerging approaches to tailor the work function and improve electron emission such as the modication of emitter geometry, the introduction of impurity, decoration of metals and the vertical alignment of the structures have been reported. 2,10 The implantation of elements into ZnO nanowires was found to produce nanoscale protuberances and surface-related defects which reduced the turn-on eld (E on ) from 3.1 to 2.4 V mm À1 (at 0.1 mA cm…”

“…Wide bandgap transition metal oxides such as NbO 2 , TiO 2 , CuO and SnO are known for their stability and are found to be suitable for eld emission in their 1D forms such as wires, rods, tubes, needles etc. [1][2][3][4] Even though ZnO is an attractive material for diverse applications in solar cells, catalysis, sensing, photocatalysis, smart windows, photoluminescence, supercapacitors, generators etc., and is even more suitable for ultraviolet light emitters and laser diodes, 4,5 it has only been moderately considered for use in FE displays because of its larger work function in the range of 5.3 to 5.6 eV, limited morphological forms and eld screening effect from uncontrolled dispersion. [6][7][8][9] Therefore, emerging approaches to tailor the work function and improve electron emission such as the modication of emitter geometry, the introduction of impurity, decoration of metals and the vertical alignment of the structures have been reported.…”