Single-Step Plasma Synthesis of Carbon-Coated Silicon Nanoparticles
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- 作者：Rohan P. Chaukulkar ; Koen de Peuter ; Paul Stradins ; Svitlana Pylypenko ; Jacob P. Bell ; Yongan Yang ; Sumit Agarwal
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2014
- 出版时间：November 12, 2014
- 年：2014
- 卷：6
- 期：21
- 页码：19026-19034
- 全文大小：430K
- ISSN：1944-8252
文摘
We have developed a novel single-step technique based on nonthermal, radio frequency (rf) plasmas to synthesize sub-10 nm, core鈥搒hell, carbon-coated crystalline Si (c-Si) nanoparticles (NPs) for potential application in Li+ batteries and as fluorescent markers. Hydrogen-terminated c-Si NPs nucleate and grow in a SiH4-containing, low-temperature plasma in the upstream section of a tubular quartz reactor. The c-Si NPs are then transported downstream by gas flow, and are coated with amorphous carbon (a-C) in a second C2H2-containing plasma. X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and in situ attenuated total reflection Fourier transform infrared spectroscopy show that a thin, < 1 nm, 3C-SiC layer forms at the c-Si/a-C interface. By varying the downstream C2H2 plasma rf power, we can alter the nature of the a-C coating as well as the thickness of the interfacial 3C-SiC layer. The transmission electron microscopy (TEM) analysis is in agreement with the Si NP core size determined by Raman spectroscopy, photoluminescence spectroscopy, and XRD analysis. The size of the c-Si NP core, and the corresponding light emission from these NPs, was directly controlled by varying the thickness of the interfacial 3C-SiC layer. This size tunable emission thus also demonstrates the versatility of this technique for synthesizing c-Si NPs for potential applications in light emitting diodes, biological markers, and nanocrystal inks.