Size and structural characterization of Si nanocrystal aggregates from a low pressure nonthermal plasma reactor
Size and structural characterization of Si nanocrystal aggregates from a low pressure nonthermal plasma reactor
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DOI：
10.1016/j.powtec.2020.06.026
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发表时间：
2020-08-01
影响因子：
5.2
通讯作者：
Hogan, Christopher J., Jr.
中科院分区：
文献类型：
--
作者：
Chen, Xiaoshuang;Seto, Takafumi;Hogan, Christopher J., Jr.
由于等离子体中存在单极负电荷，因此可以在直径分布较窄的低压等离子体中合成硅纳米晶体。然而，nc必须进入一个空间余辉，在那里nc可以释放和聚集。我们使用低压差迁移率分析和定量TEM图像分析来检查从2 Torr Ar-SiH4等离子体反应器中取样的Si NCs。我们发现，Si纳米颗粒主要由20个或更少的初级颗粒组成，其带正电荷和带负电荷的纳米颗粒浓度几乎相等。聚合体的投影面积随聚合体体积的变化与观测到的来自大气压力系统的聚合体的变化相似。随着流速的增大，集料浓度增大，而随着前驱体浓度的增大，集料粒径增大。测量结果表明，空间余辉对纳米粒子的电荷和聚集程度有显著影响。(C) 2020 Elsevier B.V.版权所有
Si nanocrystals (NCs) are synthesizable in low-pressure plasmas with narrow diameter distributions because of unipolar negative charging in the plasma. However, NCs must pass into a spatial afterglow, where NCs may decharge and aggregate. We use both low-pressure differential mobility analysis and quantitative TEM image analysis to examine Si NCs sampled from a 2 Torr Ar-SiH4 plasma reactor. We find that Si NCs are incorporated into aggregates largely composed of 20 and fewer primary particles with nearly equal concentrations of negatively and positively charged NCs. The projected areas of aggregates scale with aggregate volume in similar manner to the scaling observed for aggregates from atmospheric pressure systems. Higher aggregate concentration is observed with increasing flow rate, while larger aggregate size is found with increasing precursor concentration. Measurements show that the spatial afterglow has a significant influence on the charge and extent of NC aggregation. (C) 2020 Elsevier B.V. All rights reserved.