Electron field emission from hydrogen-free amorphous carbon-coated ZnO tip array

Abstract

Articles you may be interested inImproved conductivity of aluminum-doped ZnO: The effect of hydrogen diffusion from a hydrogenated amorphous silicon capping layer Noise characteristics of emission current from conductive diamond-like carbon thin films coating on cone shaped silicon field emitters Enhanced electron field emission from hydrogen-free amorphous carbon ͑a-C͒ films deposited on ZnO-tip-array-coated Si substrates was studied. Both the ZnO tip array and the a-C films were deposited by filtered arc deposition. Compared with the a-C film deposited on Si substrates, the a-C film on ZnO had a lower threshold field ͑4.5 V/m͒, higher field emission current density ͑0.215 mA/cm 2 at 14.3 V/m͒ and higher emission site density ͑Ͼ2ϫ10 3 /cm 2 at 20 V/m͒. The introduction of the ZnO tip array provides high local geometric electric-field enhancement for the a-C film. On the other hand, the amount of excess Zn in the ZnO film provides better conductivity. The result is that the electrons can be easily penetrated into the a-C films, which enhances the field emission properties.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…It was found that the dimensions of ZnO nanowires could be controlled from 25 to 80 nm by the varying the ZnCl 2 concentration [121]. Notably, Cl − ions became adsorbed preferentially on the Zn-terminated (0001) planes of ZnO, which eventually hindered the growth along the polar axis, giving rise to platelet-like crystals [124], even though the anions are not considered as reactants according to equations (11) and (12). Even when other zinc salts rather than ZnCl 2 were used as precursors, the Cl − could also come from the supporting electrolyte KCl [125].…”

“…It has also been suggested that when using Zn(NO 3 ) 2 as the precursor, reduction of NO 3 − at the cathode could also provide a possible source of OH − [122], as indicated by equation (12). In any case, the ratio between the OH − generation rate at the cathode and the Zn 2+ diffusion rate to the cathode was proposed to be the major parameter in the electrodeposition of ZnO nanowires [123].…”

“…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 of Zinc Oxide Nanorods with the Thickness of Less than or Equal to 1 μm through Zinc Acetate or Zinc Nitrate for Perovskite Solar Cell Applications

“…Studies of zinc oxide (ZnO) material, specifically ZnO nanorod (NR) or nanowire (NW) morphology, are continuously performed because of numerous applications of ZnO NRs in many fields of science, especially in branches of electronics, optoelectronics, electrochemistry, and electromechanics [1][2][3][4][5][6]. Some examples of these applications are ultraviolet (UV) lasers [7,8], light-emitting diodes [9], field-emission devices [10][11][12], high-performance nanosensors [13,14], solar cells [15][16][17][18], piezoelectric nanogenerators [19][20][21], and nano-piezotronics [22,23]. ZnO NR is one of the most frequently used forms of nanostructures because of its ease of fabrication by relatively less complicated methods.…”

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphologies

“…Once doped, they display new properties, e.g., electrical conductivity, magnetic, magneto-optical, photocatalytic, antibacterial and optical [ 74 , 161 , 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 , 228 , 229 , 230 , 231 , 232 ]. At present, various ZnO nanostructures are being used in attempts to produce a new generation of light-emitting diodes [ 233 , 234 ], lasers [ 235 ], field emission devices [ 236 , 237 ], memory carriers [ 238 , 239 ], solar cells [ 240 , 241 , 242 , 243 , 244 , 245 , 246 ], liquid crystals [ 247 ], polymer nanocomposites [ 248 , 249 , 250 , 251 ], food packaging materials [ 252 , 253 , 254 , 255 , 256 , 257 , 258 ], transparent ultraviolet light absorbers in unplasticised polymers [ 259 ], catalysts [ 260 ], photoluminescent NPs [ 261 ], photocatalysts ...…”