Synthesis of Thin Walled Carbon Nanotubes by Cold-Walled and Hot-Walled CVD
2010
Hochschulschrift
Zugriff:
98
This research is devoted to synthesize carbon nanotubes by different reaction chamber and different reaction temperature. We studied the morphology of carbon nanotubes by changing the reaction parameters such as reaction temperature, the ratio of carbon source and hydrogen, and reaction time. The study was divided into two parts: (1) synthesis of vertically aligned single and thin walled carbon nanotubes by cold-walled CVD and (2) synthesis of carbon nanotubes by hot-walled CVD. In the first part of the research, we used Fe metal particle and silicon wafer as the catalyst and substrate, respectively. When the Rm ratio (H2/C2H2) was 0.25, the vertically aligned single and thin walled carbon nanotubes can be grown at 850 ℃ in 60 min. The length of the vertically aligned carbon nanotubes was 206 ~ 210 μm, and the single and double walled carbon nanotubes were found to be the majority in the products. We fabricated 77 dots of the vertically aligned carbon nanotubes on selective area by lithography process. The size of each dot was about 300 x 300 μm. The vertically aligned carbon nanotubes were used as field emitter. According to the result of the field emission, the 77 dots of the vertically aligned carbon nanotubes had good field emission property. The turn-on field and field enhancement factor of the 77 dots were about 1.97 ~ 2 V/μm and 6053.5, respectively. In the second part of the research, Fe/Al bilayer and silicon were used as the catalyst and substrate. When the Rm ratio was 6.7, the carbon nanotubes thin film can be grown at 500 ℃ in 30 min. The diameter of the carbon nanotubes was 20 ~ 30 nm, and the products were multi-walled carbon nanotubes. We analyze the electrical resistivity and transmittance of the carbon nanotubes thin film by four point probe and UV-VIS, respectively. With the reaction time was 30 min, the surface resistivity of the carbon nanotubes thin film was about 2.40 kΩ/□. However, the transmittance of the carbon nanotubes thin film was just about 0.96 %. According to the result of the experiment data, we found that the surface resistivity of the carbon nanotubes thin film decreased with decreasing the transmittance of the carbon nanotubes thin film.
Titel: |
Synthesis of Thin Walled Carbon Nanotubes by Cold-Walled and Hot-Walled CVD
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Autor/in / Beteiligte Person: | Chen, Hung-Ting ; 陳皇廷 |
Link: | |
Veröffentlichung: | 2010 |
Medientyp: | Hochschulschrift |
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