Efficient field emission from ZnO nanoneedle arrays

Abstract

Well-aligned arrays of ZnO nanoneedles were fabricated using a simple vapor phase growth. The diameters of the nanoneedle tips are as small as several nanometers, which is highly in favor of the field emission. Field-emission measurements using the nanoneedle arrays as cathode showed emission current density as high as 2.4 mA/cm2 under the field of 7 V/μm, and a very low turn-on field of 2.4 V/μm. Such a high emission current density is attributed to the high aspect ratio of the nanoneedles. The high emission current density, high stability, and low turn-on field make the ZnO nanoneedle arrays one of the promising candidates for field-emission displays.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…It has been demonstrated to have enormous applications in electronic, optoelectronic, electrochemical, and electromechanical devices [3][4][5][6][7][8], such as ultraviolet (UV) lasers [9,10], light-emitting diodes [11], field emission devices [12][13][14], high performance nanosensors [15][16][17], solar cells [18][19][20][21], piezoelectric nanogenerators [22][23][24], and nanopiezotronics [25][26][27]. One-dimensional (1D) ZnO nanostructures have been synthesized by a wide range of techniques, such as wet chemical methods [28][29][30], physical vapor deposition [31][32][33], metal-organic chemical vapor deposition (MOCVD) [34][35][36], molecular beam epitaxy (MBE) [37], pulsed laser deposition [38,39], sputtering [40], flux methods [41], eletrospinning [42][43][44], and even top-down approaches by etching [45].…”

Growth mechanism and characterization of zinc oxide microcages

“…A number of nanometer and micrometer ZnO materials of varied geometries have been produced, e.g. nanowires, nanosprings, nanoneedles, nanowalls, coaxial cables, tubes, tetrapods and sheets [4][5][6][7][8][9][10][11][12][13][14][15][16].…”

Synthesis, luminescence properties and EPR investigation of hydrothermally derived uniform ZnO hexagonal rods

“…ZnO is an environment friendly material and biocompatible which is desirable especially for biomedical applications. The excellent optical properties of ZnO such as a wide direct band gap (3.37 eV) and large exciton binding energy (60 meV) at room temperature endow ZnO as a promising material for short wavelength optoelectronic devices, self-powered nanosystems, sensors, ultraviolet lasers and field-emission devices [6][7][8][9][10].…”