排序方式: 共有38条查询结果,搜索用时 31 毫秒
11.
高氮含量氮化碳微粉的制备 总被引:1,自引:0,他引:1
利用常压脉冲电弧等离子体在氮气氛下裂解二氰二胺有机晶体制备含C-N键的碳氮前驱物,然后将该前驱物置于微波氮等离子体中处理,研究了具有高氮含量氮化碳微粉的合成。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)分析了样品的形貌、成分和结构。研究结果表明:在电弧等离子体的作用下二氰二胺分子发生断键,得到碳氮直接相连的分子碎片吸附在微晶二氰二胺上。样品经脉冲电弧等离子体多次处理,其中的二氰二胺有机晶体结构被破坏,主要产物为含sp3C-N单键的非晶态碳氮化合物。非晶态的碳氮化合物在微波氮等离子体的作用下重组结晶,XPS分析表明样品表面主要由非晶碳和含有大量sp3C-N单键的高氮含量的碳氮结构组成,XRD分析表明碳氮微粉中有β-C3N4晶体相的存在。 相似文献
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微波等离子体化学气相沉积法低温制备直纳米碳管膜 总被引:7,自引:0,他引:7
Among the three main methods for the synthesis of carbon nanotubes (CNTs), chemical vapor deposition (CVD) has received a great deal of attention since CNTs can be synthesized at significantly low temperature. Plasma chemical vapor deposition methods can synthesize CNTs at lower temperature than thermal CVD. But in the usual catalytic growth of CNTs by CVD, CNTs are often tangled together and have some defects. These will limit the property research and potential applications. How to synthesize the straight CNTs at low temperature becomes a challenging issue. In this letter, straight carbon nanotube (CNT) films were achieved by microwave plasma chemical vapor deposition (MWPCVD) catalyzed by round Fe-Co-Ni alloy particles on Ni substrate at 610℃. It was found that, in our experimental condition, the uniform growth rate along the circumference of round alloy particles plays a very important role in the growth of straight CNT films. And because the substrate is conducting, the straight CNT films grown at low temperature may have the benefit for property research and offer the possibility to use them in the future applications. 相似文献
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本研究在自制的5 kW大功率MPCVD装置中,利用边缘效应成功的在基片边缘处以50μm/h的沉积速率沉积出品粒尺寸达500 μm左右的大颗粒金刚石并以70μm/h沉积速率同质外延修复长大了一颗天然的单晶金刚石.在实验中,利用SEM和Raman光谱对基片边缘区域和中央区域所沉积的金刚石颗粒进行了表征.结果表明,边缘处沉积的金刚石颗粒与中央区域沉积的金刚石颗粒相比,具有更大的晶粒尺寸和更好的质量.通过仔细观察实验条件,对边缘效应产生的原因进行了分析,发现由于基片边缘放电,使得基片表面的电场强度和温度分布发生变化,从而导致基片边缘区域的等离子体密度和温度高于中央区域,高等离子体密度和温度的综合作用是使得在基片边缘能以较高的沉积速率沉积出大尺寸金刚石颗粒的主要原因. 相似文献
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介绍了一台低成本的常压微波等离子体炬设备,给出了该设备构造及喷嘴的设计思路,分析了各种气体的非磁化微波等离子体的击穿电场强度,数值求解了设备中矩形TE103谐振腔中的电磁场分布,应用高频电磁场模拟分析软件HFSS优化了喷嘴在波导中的具体位置,并对优化后喷嘴周围的电场分布进行了模拟。模拟结果表明:微波输入有效功率为500 W,喷嘴伸出矩形波导1 mm时,喷嘴尖端处的电场强度在1.2×106 V·m-1以上,远大于氩气的击穿电场强度,更易于等离子体炬的激发。实验结果证明了模拟结果的正确性和装置的有效性。 相似文献
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利用大气微波等离子体射流(MPJ)技术对H2S气体进行了处理研究。考察了温度、微波功率、载气(Ar)流量及气源总流量对H2S分解效率的影响。实验结果表明,为了有利于H2S的处理,必须将温度控制在一定范围之内;随着微波功率和载气流量的增加,H2S分解率均是先增加后减小;随着气源总流量的增加,H2S分解率逐渐降低。当H2S与Ar气体流量比达到10∶90,总流量为1000 mL/min,微波功率为1000 W时,H2S的分解率达到最佳值91.32%。对处理后得到的固体物质进行拉曼(Raman)光谱和X射线衍射分析(XRD)分析,结果表明回收得到的固体物质为纯度极高的硫。 相似文献
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The high deposition of microcrystalline silicon thin film by very high frequency plasma enhanced
chemical vapour deposition and the fabrication of solar cells 下载免费PDF全文
This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with Hchemical vapour deposition,
plasma deposition, solar cells, crystallinity Program supported by the State Key
Development Program for Basic Research of China (Grant No
2006CB202601), and Basic Research Project of Henan Province in China
(Grant No 072300410140). 7280N, 7830G, 8115H This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with Hchemical vapour deposition,
plasma deposition, solar cells, crystallinity Program supported by the State Key
Development Program for Basic Research of China (Grant No
2006CB202601), and Basic Research Project of Henan Province in China
(Grant No 072300410140). 7280N, 7830G, 8115H This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with Hchemical vapour deposition,
plasma deposition, solar cells, crystallinity Program supported by the State Key
Development Program for Basic Research of China (Grant No
2006CB202601), and Basic Research Project of Henan Province in China
(Grant No 072300410140). 7280N, 7830G, 8115H This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with Hchemical vapour deposition,
plasma deposition, solar cells, crystallinity Program supported by the State Key
Development Program for Basic Research of China (Grant No
2006CB202601), and Basic Research Project of Henan Province in China
(Grant No 072300410140). 7280N, 7830G, 8115H This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with H$_{2}$ prior to plasma ignition, and selecting
proper discharging time after silane flow injection. Material
prepared under these conditions at a deposition rate of 0.78\,nm/s
maintains higher crystallinity and fine electronic properties. By
H-plasma treatment before i-layer deposition, single junction $\mu
$c-Si:H solar cells with 5.5{\%} efficiency are fabricated. 相似文献
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