Formation and Transistor Behavior of Carbon Nanotube T-junctions

2003 ◽  
Vol 772 ◽  
Author(s):  
Po-Wen Chiu ◽  
Jean-Michel Benoit ◽  
Ralf Graupner ◽  
Ursula Dettlaff ◽  
Siegmar Roth
Keyword(s):  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Three Dimensions ◽  
Vibration Modes ◽  
Metal Contacts ◽  
Transistor Channel ◽  
Si Substrates ◽  
Chemically Modified ◽  
Functionalized Nanotubes

AbstractWe present the formation of intermolecular nanotube junctions and investigations of their transistor behavior. T-shape junctions were formed by coupling chemically functionalized nanotubes with molecular linkers. An end-to-side or end-to-end heterojunction can be formed by reacting chloride terminated nanotubes with aliphatic diamine. The chemically modified nanotube mats were characterized by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The incorporation of functional groups into nanotubes are first identified by XPS. The carbon binding energy shifts due to the doping effect by attached functional groups. This also leads to a pronounced shift of tangential vibration modes in Raman spectra. To investigate the electrical transport, functionalized nanotubes were deposited on Si substrates, and metal contacts were applied on top of the selected T-shape junctions. The bar of the “T” is used as a transistor channel and the leg of the “T” is used as a gate. In this configuration, the active area is confined to a few nanometers in all three dimensions and gain values of 100 and above are obtained.

Carbon Nanotube T Junctions: Formation and Properties

2008 ◽  
Vol 8 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Po-Wen Chiu
Keyword(s):  
Carbon Nanotube ◽  
Photoelectron Spectroscopy ◽  
Three Dimensions ◽  
Photoelectron Spectra ◽  
Transistor Channel ◽  
X Ray ◽  
Si Substrates ◽  
Lift Off ◽  
Linker Molecules ◽  
Functionalized Nanotubes

The formation of carbon nanotube T junctions (CNTJs) and their transport properties are reviewed. The CNTJs were formed by coupling chemically functionalized nanotubes with linker molecules. Both end-to-side and end-to-end intermolecular junctions can be assembled by reacting chloride terminated nanotubes with aliphatic diamines. The functionalized nanotube mats were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy. The incorporation of functional groups into nanotubes is indicated by the pronounced shift of tangential vibration modes in Raman spectra and of carbon 1s binding energy in X-ray photoelectron spectra. For transport measurements the functionalized nanotubes were adsorbed on Si substrates, and subsequent electrodes were painted on top of the selected T junctions by lithography and lift-off techniques. The bar of the "T" is used as the transistor channel and the stem of the "T" is used as the gate. In this configuration, the active area is confined to a few nanometers in all three dimensions.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Growth of SiOx Nanowires by Simple Vapor Transport Method and their Optical Properties

2013 ◽  
Vol 534 ◽  
pp. 141-145 ◽  
Author(s):  
Yuto Hakamada ◽  
Shunji Ozaki
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Silicon Monoxide ◽  
Vapor Transport ◽  
X Ray ◽  
Si Substrates ◽  
Vls Growth ◽  
Transport Method ◽  
Vapor Transport Method ◽  
Scanning Electron

SiOx nanowires were grown on Si substrates by a simple vapor transport method of heating the mixture of silicon monoxide and carbon powders at 1000 °C in a tube of the furnace. The dependence of the growth velocity on the growth temperature and on the radius of nanowires indicates that the SiOx nanowires grow through the vaporliquidsolid (VLS) growth mechanism. The properties of the nanowires are characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL).

scholarly journals Phosphated Avocado Seed: A Renewable Biomaterial for Preparing a Flame Retardant Biofiller

2021 ◽  
Author(s):  
DAVID Zuluaga-Parra ◽  
L.F Ramos-deValle ◽  
Saul Sanchez ◽  
J.R. Torres-Lubián ◽  
J.A. Rodríguez-Gonzalez ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Modification ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Morphological Changes ◽  
Ethylene Vinyl Acetate ◽  
Chemically Modified ◽  
Air Atmosphere ◽  
Thermal Stability Of ◽  
Avocado Seed

Abstract The cellulose and starch present in the avocado seed can be chemically modified to obtain biofillers with fire retarding characteristics. The resulting composites could be used as substitute of the corresponding halogenated composites. For this, the avocado seed was first washed, dehydrated and pulverized, and thereafter, chemically modified with phosphoric acid in the presence of urea. This was studied using infrared spectroscopy, nuclear magnetic resonance and X-Ray photoelectron spectroscopy, in order to determine the resulting chemical structure and confirm the presence of the proposed functional groups. In addition, scanning electron microscopy and elemental analysis were used, respectively, to establish the resulting morphological changes, as well as the elements present on the surface of the modified material. Thermogravimetric analysis was also carried out in order to establish the thermal stability of the material and predict the effect on the flame retardancy due to the mentioned chemical modification. Further tests established that the obtained modified structure and morphology of the avocado seed was highly dependent on the method used to dehydrate the pulverized avocado seed. It was also determined that chemical modification greatly increased the thermal stability of the avocado seed in air atmosphere. The flame-retardant effect of the modified avocado seed was assessed in polyethylene/ethylene-vinyl-acetate (PE/EVA) composites via cone calorimeter tests. These results showed that the modified avocado seed decreased the peak of the heat release rate (pHRR) by 50% and the total heat released (THR) by 15%. This phosphated avocado seed could be a good option as a renewable biofiller for polymer composites with enhanced flame-retardant properties.

scholarly journals Effect of synthesis conditions  on  methylene blue adsorption capacity of electrochemically preparated graphene

2020 ◽  
Vol 9 (3) ◽  
pp. 9-14
Author(s):  
Hao Pham Van ◽  
Linh Ha Xuan ◽  
Oanh Phung Thi ◽  
Hong Phan Ngoc ◽  
Huy Nguyen Nhat ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Capacity ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Graphene Nanosheets ◽  
Electrochemical Exfoliation ◽  
X Ray ◽  
Synthesis Conditions ◽  
Mb Adsorption

This report presents the effect of synthesis conditions on the synthesis of graphene nanosheets via electrochemical exfoliation method for adsorbing methylene blue from aqueous solution. Oxygen-containing functional groups and defects in the material were characterized by Raman and X-ray photoelectron spectroscopy (XPS). As a result, by using voltage of 15 V, (NH4)2SO4 (5%, 250 mL) and KOH (7.5%, 250 mL), the obtained material showed the highest MB adsorption capacity due to the high densities of oxygen-containing groups and defects comparison to other conditions.

Single Source CVD of LiAlO2

1997 ◽  
Vol 495 ◽  
Author(s):  
Wonyong Koh ◽  
Su-Jin Ku ◽  
Yunsoo Kim
Keyword(s):  
Photoelectron Spectroscopy ◽  
Profile Analysis ◽  
Chemical Vapor ◽  
Single Source ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Si Substrates ◽  
Metal Contents ◽  
Deposited Film ◽  
Heterometallic Compound

ABSTRACTWe successfully deposited LiAlO2 films on Si substrates at 400–600 °C by single source chemical vapor deposition using a heterometallic compound, Li(O'Pr)2Al(CH3)2, which contains Li, Al, and O at the same 1:1:2 ratio as LiAlO2. Li(O'Pr)2Al(CH3)2 is sufficiently volatile to be vapor-transported at 50 °C. Elastic recoil detection and Rutherford backscattering spectroscopy analyses of a deposited film indicate that the film is stoichiometric (Li:Al:O = 1.0:1.0:2.0) and contains a few atomic percent hydrogen (5 %) and carbon (2 %). Depth profile analysis of X-ray photoelectron spectroscopy also confirms the 1:1 ratio of metal contents in the films. As-deposited films were amorphous, however, crystallized to β- or γ-LiA1O2 after annealing at 950 °C.

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