CuO nanowire field emitter arrays were synthesized from Cu films by thermal oxidation in different water vapor containing environments. It is found that thermal oxidation in the water vapor environment could increase the density of CuO nanowires. The field emission properties of the CuO nanowires prepared under different conditions were studied and compared. Uniform CuO nanowire field emitter arrays with optimal field emission properties were obtained.

G. X. Liu;军 陈;少芝 邓;宁生 许

2011

We study the field emission characteristics of large-area films of crystalline MoO₃ microbelt grown on silicon substrate by thermal evaporation in air using a commercial infrared sintering furnace. It is found that their turn-on field, threshold field, resistance to microdischarge and field emission current stability are better than MoO₃ nanowires, MoO ₃ nanobelts and MoO₃ nanoflower. In addition, good uniform distribution of field emission sites can be observed. The physical reasons are explained responsible for such improvements on field emission characteristics of MoO ₃ material. These results indicate that large-area MoO ₃ microbelts may be suitable for cold-cathode electron source application.

少芝 邓;Dongmei Ban;宁生 许;军 陈;峻聪 佘;Fei Liu

Journal of Nanomaterials

2010

Field emission property of aligned and random SiC nanowires arrays synthesized by a simple vapor-solid reaction was investigated, respectively. A better field emission property with a turn-on field of ∼10.5 MV/m for oriented nanowires array was obtained while the higher value of ∼29.5 MV/m for disordered nanowires array was received. After comparison, highly aligned and high-quality SiC nanowires with high aspect ratio contributed the better field-emitting property.

Jun Jie Niu;健农 王;宁生 许

Solid State Sciences

2008-5

Details are given of experiments carried out to compare the field electron emission characteristics of single crystal silicon tip arrays with and without amorphous diamond coating. The coatings on the tip arrays were prepared using filtered vacuum arc plasma deposition technique. The morphology of the coating was studied in a scanning electron microscope. An anode probe technique was employed to measure the I-V characteristics, stability and turn-on fields of the tip-array emitters before and after coating. It has been found that the coating has effects not only on enhancing emission, but also stabilizing it. The physical reason for these effects is discussed.

峻聪 佘;S. E. Huq;军 陈;少芝 邓;宁生 许

1998

Modulation of field emission current from ZnO nanowires (ZnO NWs) by a high voltage amorphous silicon thin film transistor (HVTFT) is reported. The emission current was modulated in about three orders of magnitude. Precise control and stabilization of emission current were achieved.

小明 陈;H. Ou;X. M. Song;W. Q. Chen;峻聪 佘;少芝 邓;宁生 许;军 陈

2015-8-26

Vertical few-layer graphene (FLG) sheets have been fabricated by using microwave-plasma-enhanced chemical vapour deposition. Their shape was manipulated through adjusting the growth time and hydrocarbon gas ratio. The growth mechanism during different growth stages is discussed. The field emission characteristics for different FLG shapes were tested and found to be strongly influenced by the tip shape, the height and the amorphous carbon content. The optimal shape of vertical FLG for field emission had fewer layers, sharp corners, large height and was free of amorphous carbon. The best field emission properties with the optimal shape were observed with a turn-on field of 1.8Vμm ^-1 and maximum current density of 7mAcm ^-2.

Yu Zhang;Jiale Du;Shuai Tang;Pei Liu;少芝 邓;军 陈;宁生 许

Nanotechnology

2012-1-13

The epitaxial growth of carbon nanotubes (CNTs) is an important subject of research. Recent attention has been paid to finding new strategies for the controlled growth of single-wall CNTs with a defined chirality. In addition, many potential applications require multiwall CNTs (MWCNTs) to grow vertically from the substrate and the interface property is crucial. Here, we report for the first time that MWCNTs can grow directly from the surface of a substrate by epitaxy, based on the experimental study of individual multiwall carbon nanotubes on a large-area stainless steel substrate, which is a very useful system for electrical and mechanical applications. In particular, evidence is given of the lattice matching between the MWCNT and the lattice of a hexagonal Cr₂O₃: (Fe, Mn) film formed on the surface of the substrate. Furthermore, a method is developed to increase the density of the MWCNTs; a mechanism of simultaneous top and bottom growth is proposed. The resultant significantly improved electrical transport and field emission properties are also presented, showing the Ohmic contact for electrical conduction and high performance in resisting the catastrophic cold-cathode vacuum breakdown of the CNTs.

Weiwei Zhu;Yu Zhang;宁生 许;Yuanming Tan;Runze Zhan;Yan Shen;Zhi Xu;Xuedong Bai;军 陈;峻聪 佘;少芝 邓

Nanotechnology

2017-7-6

Enhancement field emission current from iron oxide nanoemitters was observed after applying a in-situ thermal treatment process in vacuum. In one thermal treatment cycle, iron oxide nanoemitters were heated to 200 °C and kept for 2 hr. Comparison of I-V characteristics before and after thermal treatment shows that the field emission current were much enhanced from 60 μA/cm² to 500 μA/cm² at electric field of 10 MV/m. The threshold electric field decreased from 20 MV/m to 12.2 MV/m. Moreover, the enhancement was retained and the field emission current does not decrease to original level after cooling down. The emission current under different gas atmosphere were studied. The results show the observed enhancement was caused by the surface gas desorption, most likely the oxygen.

J. Q. Wu;军 陈;少芝 邓;宁生 许

2011

Various types of tungsten oxide nanostructures, including nanowires, nanobundles, and three-dimensional nanowire networks, have been synthesized on large-area silicon substrates by simply heating an array of tungsten filaments in a vacuum chamber. The fine structure and components of as-prepared products can been controlled by changing the tungsten filament temperature. This approach is free of catalysts and templates, and provides an economical method for large-scale preparation of various types of tungsten oxide nanostructures for applications.

Lingfei Chi;宁生 许;少芝 邓;军 陈;峻聪 佘

Nanotechnology

2006-11-28

Abstract: For the first time, Mo nanoscrew was cultivated as a novel non-coinage-metal substrate for surface-enhanced Raman scattering (SERS). It was found that the nanoscrew is composed of many small screw threads stacking along its length direction with small separations. Under external light excitation, strong electromagnetic coupling was initiated within the gaps, and many hot-spots formed on the surface of the nanoscrew, which was confirmed by high-resolution scanning near-field optical microscope measurements and numerical simulations using finite element method. These hot-spots are responsible for the observed SERS activity of the nanoscrews. Raman mapping characterizations further revealed the excellent reproducibility of the SERS activity. Our findings may pave the way for design of low-cost and stable SERS substrates. Graphical Abstract: Mo nanoscrews are for the first time cultivated as a novel type of SERS substrate. The SERS activity is originated from the electromagnetic field enhancements on the individual Mo nanoscrew, which is corroborated by single-particle optical characterizations[Figure not available: see fulltext.]

Di An;Yan Shen;Jinxiu Wen;Zebo Zheng;军 陈;峻聪 佘;Huanjun Chen;少芝 邓;宁生 许

Nano-Micro Letters

2017-1-1