| Summary: | 碩士 === 國立臺灣科技大學 === 光電工程研究所 === 96 === Arrays of carbon nanotube (CNT) bundles with hexagonal arrangement were synthesized by thermal chemical vapor deposition (CVD). It is known that nitrogen doping of CNTs can enhance field emission of these arrays. In this study, two methods were employed to form N-doped CNTs. (1) N-doped CNT bundle arrays were synthesized in a thermal CVD system with a mixture of C2H2 and ammonia (NH3). (2) After the synthesis of CNT bundle arrays by thermal CVD, the samples were transferred to another chamber for nitrogen plasma treatment to form nitrogen-doped vertically aligned CNT bundle arrays. The characteristics of the nitrogen-doped CNT bundles were investigated by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The results revealed that there exists an optimal synthesis condition and nitrogen content for enhancing field emission. The lowest observed threshold electric field (Eth) was 2.4 V/�慆 when 6 Torr (0.59 at.%) NH3 pressure was used and 2.3 V/�慆 after 70 min (4.08 at.%) of nitrogen plasma treatment.
|
|---|
