Large Scale Production of Carbon Nanotube Transistors: A Generic Platform for Chemical Sensors

2003 ◽  
Vol 776 ◽  
Author(s):  
Jean-Christophe P. Gabriel
Keyword(s):  
Chemical Sensors ◽  
Large Scale ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Scale Production ◽  
Statistical Characterization ◽  
Large Scale Production ◽  
Nanotube Transistors ◽  
New Formulation ◽  
Nanotube Growth

AbstractWe report our work on the fabrication of nanotube-based field effect transistors (NTFET). Nanotubes were grown by chemical vapor deposition using various approaches, including a new formulation of nanotube growth catalysts that were directly patterned using UV lithography. We also report NTFETs based on randomly oriented nanotube networks that have a modulation of one. Finally, we report that a systematical and statistical characterization of millions of devices has led to the development of a robust process that may be useful in large scale production of reproducible, nanotube-based FETs, which, in turn, can be used as a generic platform for chemical sensors.

Industrial Synthesis of Whisker Carbon Nanotubes

2016 ◽  
Vol 852 ◽  
pp. 514-519 ◽  
Author(s):  
Xiao Gang Sun ◽  
Zhi Wen Qiu ◽  
Long Chen ◽  
Man Yuan Cai ◽  
Zhi Peng Pang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Large Scale ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Scale Production ◽  
Multiwalled Carbon ◽  
Large Scale Production ◽  
New Type

Since the first observation of carbon nanotubes (CNTs) in 1991, their synthesis techniques has been extensively investigated. The chemical vapor deposition (CVD) process have attracted much attention because of both their versatility and easy large scale production for CNTs . This paper is focused on a catalytic CVD-based method for synthesis of whisker multiwalled carbon nanotubes (WMWCNTs). The new type of carbon nanotube is similar to the whisker. The morphology of the WMWCNTs are very different from traditional carbon nanotubes prepared by traditional chemical vapor deposition process. The traditional CNTs were twisted and entangled with each other. These suggested that there are a lot of deficiencies on the CNTs and are difficult to disperse in matrix materials. The as-produced WMWCNTs are very straight and not entangled with each other. The line structure means that WMWCNTs are easily dispersed in matrix materials than traditional CNTs which are twined together. The crystallinity of WMWCNTs increased to 96% which was much higher than traditional CNTs after graphitization treatment at 2800°C.

Large-scale Production of Selective Gas Sensors Based on Carbon Nanotube Mats Transistors

2010 ◽  
Vol 1253 ◽  
Author(s):  
Louis Gorintin ◽  
Paolo Bondavalli ◽  
pierre legagneux ◽  
Marc Chatelet
Keyword(s):  
Gas Sensors ◽  
Large Scale ◽  
Gas Sensing ◽  
Field Effect Transistors ◽  
Low Cost ◽  
Flexible Substrates ◽  
Scale Production ◽  
Metal Electrodes ◽  
Sensing Applications ◽  
Large Scale Production

AbstractThe first paper showing the great potentiality of Carbon Nanotubes Field Effect transistors (CNTFETs) for gas sensing applications was published in 2000 [1]. It has been demonstrated that the performances of this kind of sensors are extremely interesting : a sensitivity of around 100ppt (e.g. for NO2 [2]) has been achieved in 2003 and several techniques to improve selectivity have been tested with very promising results [2]. The main issues that have not allowed, up to now, these devices to strike more largely the market of sensors, have been the lack of an industrial method to obtain low-cost devices, a demonstration of their selectivity in relevant environments and finally a deeper study on the effect of humidity and the possible solutions to reduce it. This contribution deals with CNTFETs based sensors fabricated using air-brush technique deposition on large surfaces. Compared to our last contribution [3], we have optimized the air-brush technique in order to obtain high performances transistors (Log(Ion)/ Log(Ioff) ~ 5/6) with highly reproducible characteristics : this is a key point for the industrial exploitation. We have developed a machine which allows us the dynamic deposition on heated substrates of the SWCNT solutions, improving dramatically the uniformity of the SWCNT mats. We have performed tests using different solvents that could be adapted as a function of the substrates (e.g. flexible substrates). Moreover these transistors have been achieved using different metal electrodes (patented approach [4]) in order to improve selectivity. Results of tests using NO2, NH3 with concentrations between ~ 1ppm and 10ppm will be shown during the meeting.

Atomic Scale Investigation of Nanoparticle and Fabrication Temperature Effects on Carbon Nanotube Diameter and Chirality

2008 ◽  
Author(s):  
Mahmoud Reza Hosseini ◽  
Nader Jalili ◽  
Rebecca M. Alway-Cooper
Keyword(s):  
Vapor Deposition ◽  
Large Scale ◽  
Md Simulation ◽  
Chemical Vapor ◽  
Atomic Scale ◽  
Scale Production ◽  
Energy Increase ◽  
Nanoelectronic Devices ◽  
Large Scale Production ◽  
Percent Increase

Carbon nanotubes (CNTs) are one of the best candidates for utilizing in the future nanoelectronic devices. However, the semiconductivity property of CNTs varies as diameter and chirality number change. Several nanoelectronic applications require semiconductivity to be of a certain value with little variability. Therefore, it is necessary to reliably produce uniform CNTs with unique diameter and chirality. However, this still remains one of the challenging problems in the large scale production and application of CNTs. In this paper, the effect of fabrication temperature change on CNTs diameter and chirality are experimentally and theoretically studied. Utilizing chemical vapor deposition (CVD) fabrication process and by conducting experimental investigation, it is observed that a CNT possesses a larger diameter at its base compared to the section far away from deposited nanoparticles. Moreover, using MD simulation technique, it is observed that the energy of the CNTs molecular structure will increase by applying higher fabrication temperature. Usually this energy increase is greater in the thicker CNTs. However, the energy increase percentage is found to be affected by the chirality of the CNT. Among CNTs of the same diameter, the armchair conformation has the highest percent increase, followed by the chiral CNTs, and the zigzag nanotube has the lower percent increase. The obtained results can be utilized in a controllable CNTs diameter and chirality design process.

Large-scale production of titania nano-coated silica-gel beads by fluidized bed chemical vapor deposition

2007 ◽  
Vol 24 (2) ◽  
pp. 347-349 ◽  
Author(s):  
Jaehyeon Park ◽  
Dal Hee Bae ◽  
Seung Yong Lee ◽  
Jini Kwak ◽  
Hai Woong Park ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Fluidized Bed ◽  
Silica Gel ◽  
Vapor Deposition ◽  
Large Scale ◽  
Chemical Vapor ◽  
Scale Production ◽  
Gel Beads ◽  
Large Scale Production

scholarly journals Characterization of MOCVD-Prepared CIS Solar Cells

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7721
Author(s):  
Seung Hoon Lee ◽  
Gyu Hyun Lee ◽  
Hae-Seok Lee ◽  
Donghwan Kim ◽  
Yoonmook Kang
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Chemical Vapor ◽  
Energy Conversion Efficiency ◽  
Production Costs ◽  
Organic Chemical ◽  
Scale Production ◽  
Photovoltaic Devices ◽  
Large Scale Production ◽  
Cigs Solar Cells

Chalcopyrite Cu(In,Ga)Se2 (CIGS) solar cells prepared via metal-organic chemical vapor deposition (MOCVD) are one of the candidates for highly advanced photovoltaic devices. This is because of their effectiveness and potential for reducing production costs through large-scale production. However, research on MOCVD-prepared solar cells is progressing slower than that on other types of solar cells, primarily because the preparation of CuInSe2 (CIS)-based films via MOCVD is relatively more sophisticated. In this study, we analyzed CIS solar cells prepared via three-stage MOCVD and processed with relatively simple precursors and techniques. We achieved an energy-conversion efficiency of 7.39% without applying a buffer layer. Instead, we applied a Cu-deficient layer to create a buried pn junction. Ultimately, we demonstrated that the fabrication of fully-MOCVD-processed CIS photovoltaic devices is feasible.

A novel synthesis of carbon nanotubes directly from an indecomposable solid carbon source for electrochemical applications

2016 ◽  
Vol 4 (6) ◽  
pp. 2137-2146 ◽  
Author(s):  
Zhi Zhang ◽  
Shichun Mu ◽  
Bowei Zhang ◽  
Lu Tao ◽  
Shifei Huang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
Low Cost ◽  
Chemical Vapor ◽  
Scale Production ◽  
Solid Carbon ◽  
Novel Approach ◽  
Large Scale Production ◽  
Solid Carbon Source ◽  
Synthesis Of Carbon Nanotubes

Carbon nanotubes (CNTs) are firstly synthesized through a novel low cost self-vaporized chemical vapor deposition (SCVD) technique, which represents a novel approach toward large scale production of CNTs.

scholarly journals Fast-LPG Sensors at Room Temperature by α-Fe2O3/CNT Nanocomposite Thin Films

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
B. Chaitongrat ◽  
S. Chaisitsak
Keyword(s):  
Large Scale ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Catalyst Particle ◽  
Nanocomposite Films ◽  
Scale Production ◽  
Fe Catalyst ◽  
Large Scale Production ◽  
Cvd Synthesis ◽  
Surface Morphologies

We present performance of a room temperature LPG sensor based on α-Fe2O3/CNT (carbon nanotube) nanocomposite films. The nanocomposite film was fabricated via the metallic Fe catalyst particle on CNTs in which both the catalyst particles and the CNT were simultaneously synthesized by chemical vapor deposition (CVD) synthesis and were subsequently annealed in air to create α-Fe2O3. These methods are simple, inexpensive, and suitable for large-scale production. The structure, surface morphologies, and LPG response of nanocomposite films were investigated. Raman spectroscopy and XPS analysis showed the formation of α-Fe2O3 on small CNTs (SWNTs). Morphological analysis using FE-SEM and AFM revealed the formation of the porous surface along with roughness surface. Additionally, the sensing performance of α-Fe2O3/CNTs showed that it could detect LPG concentration at lower value than 25% of LEL with response/recovery time of less than 30 seconds at room temperature. These results suggest that the α-Fe2O3/CNTs films are challenging materials for monitoring LPG operating at room temperature.

I. S. A. Baud. Forms of Production and Women's Labour: Gender Aspects of Industrialisation in India and Mexico. New Delhi: Sage Publications. 1992. 321 pp.Hardbound. Price: Indian Rs 295.00.

1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha
Keyword(s):  
Large Scale ◽  
Indian Society ◽  
New Delhi ◽  
Scale Production ◽  
Female Labour ◽  
Self Employment ◽  
Commodity Production ◽  
Large Scale Production ◽  
Mexican Society ◽  
Small Production

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.

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