An effective in situ FE (finite element) measurement system was developed by setting up a second stage inside a scanning electron microscope chamber, where the distance between the emitting source and counter electrode could be accurately measured and finely controlled. The FE property was measured on the aligned ZnO NWs with five different densities. All of them were grown on the same substrate and measured one after the other under the exact same conditions. Therefore, the total current received was determined by the size of the W tip so that the measured emission current for samples of different grown areas can be compared directly. The FE property of the aligned ZnO NWs with different densities were characterized. It was found that the NWs with a density between 60 and 80 μm 2 and of Ca. 1 μm in length gave the highest emitting current.

Xudong Wang;Jun Zhou;Changshi Lao;Jinhui Song;宁生 许;俊 周

Advanced Materials

2007-6-18

A non-lithography and non-oxidation-sharpening method for the fabrication of ultra-high density Silicon (Si) nanotip arrays, with different coating materials such as SiC, was presented. The field electron emission properties of the Si nanotip arrays with different coated layers were also analyzed. It was found that a silicon carbide (SiC) apex was present on each Si nanotip. It was observed that both silicon nanotips with a silicon layer and SiC apex possessed a low threshold field of 6 MV/m for emission.

K. Zhao;峻聪 佘;Jun Zhou;少芝 邓;军 陈;宁生 许

2004

Acid treatment was used to remove the Fe nanoparticles encapsulated in the carbon nanofibres grown by thermal chemical vapour deposition. Transmission electron microscopy was used to determine the structure of the carbon nanofibres. Field emission scanning electron microscopy and x-ray energy-dispersive spectroscopy were employed to analyse the effect of the treatment. It was found that treatment with HCl can partially remove the Fe nanoparticles on tips. Treatment using a mixture of HNO₃ and H ₂SO₄ is an effective way to remove the Fe nanoparticles on tips. Also, the tips of carbon nanofibres having Fe nanoparticles seem to be more stable against O₂ plasma etching than the bodies of the carbon nanofibres.

P. Wu;少芝 邓;军 陈;峻聪 佘;宁生 许

Surface and Interface Analysis

2004

The phase transformation from amorphous carbon to nanodiamond has been achieved by pulsed-laser irradiation of amorphous carbon films in a confined liquid at room temperature and ambient pressure. Nanocrystalline diamonds (NCDs) with size of about 4-7 nm were generated in the surface layer of amorphous carbon films by the amorphous carbon-to-diamond transition. It was found that the embedded NCDs microstructure array considerably improve the field emission performance of the treated amorphous carbon films. The physical and chemical mechanisms of the amorphous carbon-to-diamond transition induced by laser irradiation in liquid and the enhanced field emission caused by NCDs embedded in amorphous carbon films were pursued.

Pu Liu;成新 王;Jian Chen;宁生 许;国伟 杨;Ning Ke;Jianbin Xu

Journal of Physical Chemistry C

2009-7-16

R. Z. Zhan;军 陈;少芝 邓;宁生 许

2009

Hemispherical Au-Ag alloy nanoparticles were prepared on 2-inch Si wafer by thermal annealing Au-Ag alloy thin film in protective ambient. The nanoparticles were evenly distributed on the substrate surface. The diameter of the nanoparticles is dependent of the deposition duration of the Au-Ag alloy thin film, and also the separation between the nanoparticles. The minimum and maximum diameters of the nanoparticles obtained so far are about 5 nm and 160 nm, respectively. Experimental evidences indicated that the formation of the hemispherical nanoparticles is due to the surface tensile stressing induced by the lattice expansion.

R. H. Yao;峻聪 佘;宁生 许;少芝 邓;军 陈

Journal of Nanoscience and Nanotechnology

2008-7

Decorating with metal nanoparticles (NPs) is an effective way to tune the photoluminescence (PL) properties of ZnO nanowires (NWs), but the mechanism for this is insufficiently understood. In this study, ZnO NWs with lower work function were synthesized on Si substrates using thermal oxidation. Au NPs were incorporated onto the surface of the ZnO NWs. The PL properties of ZnO NWs decorated with Au NPs of different sizes were systematically investigated. Quenching rather than enhancement of both the near-band-edge and visible emission of ZnO NWs was observed after decoration with Au NPs. Introducing an approximately 2-nm-thick Al₂O₃ insulating layer between the ZnO NWs and Au NPs caused the quenching phenomenon to disappear. These results suggest that the quenching was caused by electron transfer from ZnO to the Au NPs under UV irradiation and the PL properties of ZnO NWs decorated with Au NPs are also related to the band structure of ZnO.

Keshuang Zheng;Zhipeng Zhang;Ximiao Wang;Runze Zhan;Huanjun Chen;少芝 邓;宁生 许;军 陈

Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes

2019

Needle-shaped 3C-SiC nanowires were grown from commercially available SiC powders in a thermal evaporation process with iron as catalyst. A strong broad photoluminescence peak located around 450 nm was observed at room temperature, which may be ascribed to quantum size effects of nanomaterials. Needle-shaped 3C-SiC nanowires may have great potential applications such as blue-green light-emitting diodes and display devices.

D. H. Feng;天卿 贾;X. X. Li;至展 徐;军 陈;少芝 邓;Z. S. Wu;宁生 许

Solid State Communications

2003-11

α-Fe₂O₃ nanomaterials with different morphology parameters were prepared by varying growth temperature in the thermal oxidation process. After current aging treatment, emission current density increased from 0.05 mA/cm² to 5.70 mA/cm² under applied electrical field of 7.8 MV/m.α-Fe₂O₃ nanoflakes prepared under 350 °C exhibits low threshold field of 5.1 MV/m. Current aging treatment was carried out to improve field emission properties of α-Fe₂O₃ nanoflakes. The corresponding physical mechanism was investigated.

Junqing Wu;少芝 邓;宁生 许;军 陈

2017-9-26

We report procedure with use of self-assembled silicon carbide (SiC) nanomasks for preparation of ultrahigh-density Si nanotips. Si nanotips with SiC apex may be firstly prepared in a CH₄/H₂ plasma treatment and in a subsequent H₂ plasma etching a SiC apex may be converted into an amorphous silicon (a-Si) one with an additional function of sharpening the nanotips. A comparative study of the field electron emission from the Si nanotips with apexes of SiC, a-Si and pure Si is carried out, and shows that nanotips with a-Si apexes have not only the highest field enhancement factor but also the best emission uniformity. The physical origins for the above two improvements in field emission are discussed.

峻聪 佘;K. Zhao;少芝 邓;军 陈;宁生 许

Applied Physics Letters

2005