Exploring growth kinetics of carbon nanotube arrays by in situ optical diagnostics and modeling
Abstract
Simple kinetic models of carbon nanotube growth have been able to successfully link together many experimental parameters involved in the growth of carbon nanotubes for practical applications including the prediction of growth rates, terminal lengths, number of walls, activation energies, and their dependences on the growth environment. The implications of recent experiments utilizing in situ monitoring of carbon nanotube growth on our past kinetic model are first reviewed. Then, sub-second pulsed feedstock gas introduction is discussed to explore the nucleation and initial growth of carbon nanotubes in the context of the kinetic model. Moreover, kinetic effects in "pulsed CVD" - using repeated pulsed gas introduction to stop and restart nanotube growth - are explored to understand renucleation, the origin of alignment in nanotube arrays, and incremental growth. Time-resolved reflectivity of the surface is used to remotely understand the kinetics of nucleation and the coordinated growth of arrays. This approach demonstrates that continuous vertically aligned single wall carbon nanotubes can be grown incrementally by pulsed CVD, and that the first exposure of fresh catalyst to feedstock gas is critical to nanotubes site density required for coordinated growth. Aligned nanotube arrays (as short as 60 nm) are shown to nucleate and growmore »
- Authors:
-
- ORNL
- Oak Ridge National Laboratory (ORNL)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1133568
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Conference
- Resource Relation:
- Conference: SPIE Photonics West, San Francisco, CA, USA, 20140202, 20140202
- Country of Publication:
- United States
- Language:
- English
Citation Formats
Puretzky, Alexander A, Geohegan, David B, Pannala, Sreekanth, and Rouleau, Christopher. Exploring growth kinetics of carbon nanotube arrays by in situ optical diagnostics and modeling. United States: N. p., 2014.
Web.
Puretzky, Alexander A, Geohegan, David B, Pannala, Sreekanth, & Rouleau, Christopher. Exploring growth kinetics of carbon nanotube arrays by in situ optical diagnostics and modeling. United States.
Puretzky, Alexander A, Geohegan, David B, Pannala, Sreekanth, and Rouleau, Christopher. 2014.
"Exploring growth kinetics of carbon nanotube arrays by in situ optical diagnostics and modeling". United States.
@article{osti_1133568,
title = {Exploring growth kinetics of carbon nanotube arrays by in situ optical diagnostics and modeling},
author = {Puretzky, Alexander A and Geohegan, David B and Pannala, Sreekanth and Rouleau, Christopher},
abstractNote = {Simple kinetic models of carbon nanotube growth have been able to successfully link together many experimental parameters involved in the growth of carbon nanotubes for practical applications including the prediction of growth rates, terminal lengths, number of walls, activation energies, and their dependences on the growth environment. The implications of recent experiments utilizing in situ monitoring of carbon nanotube growth on our past kinetic model are first reviewed. Then, sub-second pulsed feedstock gas introduction is discussed to explore the nucleation and initial growth of carbon nanotubes in the context of the kinetic model. Moreover, kinetic effects in "pulsed CVD" - using repeated pulsed gas introduction to stop and restart nanotube growth - are explored to understand renucleation, the origin of alignment in nanotube arrays, and incremental growth. Time-resolved reflectivity of the surface is used to remotely understand the kinetics of nucleation and the coordinated growth of arrays. This approach demonstrates that continuous vertically aligned single wall carbon nanotubes can be grown incrementally by pulsed CVD, and that the first exposure of fresh catalyst to feedstock gas is critical to nanotubes site density required for coordinated growth. Aligned nanotube arrays (as short as 60 nm) are shown to nucleate and grow within single, sub-second gas pulses. The multiple-pulse growth experiments (> 100 pulses) show that a high fraction of nanotubes renucleate on subsequent gas pulses.},
doi = {},
url = {https://www.osti.gov/biblio/1133568},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2014},
month = {Wed Jan 01 00:00:00 EST 2014}
}