Effect of carbon nanotube pattern on the laser lift off and quantum efficiencies of near UV vertical LEDs

ABSTRACTWe describe the fabrication of self-aligned split gate electrodes on suspended multiwalled carbon nanotube structures. A suspended multiwalled carbon nanotube structure was used as an evaporation mask for the deposition of metal electrodes resulting in the formation of discontinuous wire deposition. The metal deposits on the nanotubes are removed with lift-off due to the poor adhesion of metal to the nanotube surface. Using Al sacrificial layers, it was possible to fabricate self-aligned contact electrodes and control electrodes nanometers from the suspended carbon nanotubes with a single lithography step. It was also shown that the fabrication technique may also be used to form nano-gaped contact electrodes. The technique should prove useful for the fabrication of nano-electromechanical systems.

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Lift-off patterning of multi-walled carbon nanotube and PEDOT:PSS composite films with fluorinated polymer templates

Microelectronic Engineering ◽

10.1016/j.mee.2015.06.006 ◽

2015 ◽

Vol 145 ◽

pp. 160-165 ◽

Cited By ~ 2

Author(s):

Ki-Bo Kim ◽

Myoung-Soo Kim ◽

Da-hyeok Lee ◽

Bong-Man Choi ◽

Kun-Soo Jung ◽

...

Keyword(s):

Carbon Nanotube ◽

Composite Films ◽

Fluorinated Polymer ◽

Polymer Templates ◽

Multi Walled Carbon Nanotube ◽

Lift Off

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Carbon nanotube assisted Lift off of GaN layers on sapphire

Applied Surface Science ◽

10.1016/j.apsusc.2016.10.148 ◽

2017 ◽

Vol 394 ◽

pp. 598-603 ◽

Cited By ~ 4

Author(s):

Hao Long ◽

Xiaohui Feng ◽

Yang Wei ◽

Tongjun Yu ◽

Shoushan Fan ◽

...

Keyword(s):

Carbon Nanotube ◽

Lift Off

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Carbon Nanotube T Junctions: Formation and Properties

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.n09 ◽

2008 ◽

Vol 8 (1) ◽

pp. 88-98 ◽

Cited By ~ 1

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.

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Fabrication of Carbon Nanotube Field-Effect Transistors with Metal and Semiconductor Electrodes

MRS Proceedings ◽

10.1557/proc-1057-ii15-20 ◽

2007 ◽

Vol 1057 ◽

Cited By ~ 2

Author(s):

Himani Sharma ◽

Zhigang Xiao

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Bismuth Telluride ◽

Field Effect ◽

Field Effect Transistors ◽

Single Walled Carbon Nanotubes ◽

Back Side ◽

Single Walled Carbon ◽

Lift Off ◽

Walled Carbon Nanotubes

ABSTRACTCarbon nanotube field-effect transistors (CNTFETs) were fabricated with metal material (gold) and semiconductor material (bismuth telluride) as the source and drain materials. Highly-purified HiPCO-grown single-walled carbon nanotubes (CNTs) from Carbon Nanotechnologies, Inc. (CNI) were used for the fabrication of CNTFETs. The single-walled carbon nanotubes were ultrasonically dispersed in toluene and dimethylformamide (DMF) with trifluoroacetic acid (TFA), as co-solvent. Dielectrophoresis (DEP) method was used to deposit, align, and assemble carbon nanotubes (CNTs) to bridge the gap between the source and drain of CNTFETs to form the channel. The structure of CNTFET is similar to a conventional field-effect transistor with substrate acting as a back-side gate. Electron-beam evaporation was used to deposit gold and bismuth telluride thin films. Microfabrication techniques such as photolithography, e-beam lithography, and lift-off process were used to define and fabricate the source, drain, and gate of CNTFETs. The gap between the source and drain varied from 800 nm to 3 µm. The drain-source current (IDS) of the fabricated CNTFETs versus the drain-source voltage (VDS) and the gate voltage (VG) was characterized. It was found that in the case of gold (Au) electrodes, the IV curves of CNTFETs clearly show behavior of the CNT (metallic or semiconducting) aligned across the source and drain of CNTFETs, while in the case of bismuth telluride (Bi2Te3) electrodes, the I-V curves are less dependent on the type of CNTs (metallic or semiconducting). The developed carbon nanotube field-effect transistors (CNTFETs) can be a good candidate for the application of nanoelectronics and integrated circuits with a high mobility and fast switching.

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Single-Walled Carbon Nanotube Micropatterns and Interconnections Fabricated With Layer-by-Layer Nano Self-Assembly and Microlithography on Flexible Substrates

CANEUS2006: MNT for Aerospace Applications ◽

10.1115/caneus2006-11054 ◽

2006 ◽

Author(s):

Wei Xue ◽

Tianhong Cui

Keyword(s):

Carbon Nanotube ◽

Self Assembly ◽

Low Cost ◽

Flexible Substrates ◽

Layer By Layer ◽

Single Walled Carbon Nanotube ◽

Plastic Substrates ◽

Single Walled Carbon ◽

Current Voltage ◽

Lift Off

The fabrication and characterization of single-walled carbon nanotube (SWNT) multilayers, micropatterns and interconnections on plastic substrates are reported in this paper. The SWNT-based multilayers and devices are fabricated with a simple, fast, inexpensive, low-temperature, and highly efficient technique combining layer-by-layer (LbL) nano self-assembly, microlithography, and lift-off techniques. The SWNT multilayers are alternating layers of SWNTs and poly (dimethyldiallylammonium chloride) (PDDA). Lithography and lift-off techniques are used to pattern the SWNT multilayers. SWNT microstructures with linewidth of 5 μm are fabricated and characterized. The thickness of a (PDDA/SWNT) bi-layer is approximately 76 Å. Two-terminal SWNT thin film based interconnections are fabricated on flexible substrates. Current-voltage (I-V) characterization and four-point probe measurement show that the resistance of the interconnection is nonlinearly inversely proportional to the number of the assembled SWNT layers. The nano-assembled polymer/SWNT composite can be used in many applications due to its low cost, light weight, and long lifetime.

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Micropatterned Vertically Aligned Carbon Nanotube Growth on a Si Surface or inside Trenches for field-emission devices

MRS Proceedings ◽

10.1557/proc-706-z1.6.1 ◽

2001 ◽

Vol 706 ◽

Author(s):

Jung Inn Sohn ◽

Seonghoon Lee ◽

Yoon-Ho Song ◽

Sung-Yool Choi ◽

Jin Ho Lee ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Field Emission ◽

Electronic Devices ◽

Chemical Vapor ◽

Fabrication Process ◽

Processing Technologies ◽

Field Emission Displays ◽

Vertically Aligned ◽

Lift Off

AbstractThe good field-emission properties of carbon nanotubes coupled with their high mechanical strength, chemical stability, and high aspect ratio, make them ideal candidates for the construction of efficient and inexpensive field-emission electronic devices. The fabrication process reported here has considerable potential for use in the development of integrated radio frequency amplifiers or field emission-controllable cold electron guns for field emission displays. This fabrication process is compatible with currently used semiconductor processing technologies. Micropatterned vertically aligned carbon nanotubes were grown on planar Si surface or inside the trenches, using chemical vapor deposition, photolithography, pulsed-laser deposition, reactive ion etching, and the lift-off method. To control the field-emission current by a 3rd electrode, the gate electrode, we grew carbon nanotubes inside the trenches. This triode-type structure is the best to realize the gray-scale carbon nanotube field emission. This carbon nanotube fabrication process can be widely applied for the development of electronic devices using carbon nanotube field emitters as cold cathodes and could revolutionize the area of field-emitting electronic devices such as RF amplifiers and field emission displays.

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Mechanisms in Carbon Nanotube Growth: Modelling and Molecular Dynamics Simulations

10.26686/wgtn.17003134.v1 ◽

2021 ◽

Author(s):

◽

Dmitri Schebarchov

Keyword(s):

Molecular Dynamics ◽

Carbon Nanotube ◽

Supported Catalysts ◽

Critical Role ◽

Chemical Vapour ◽

Catalyst Particle ◽

Md Simulations ◽

Capillary Absorption ◽

Supported Nickel Catalyst ◽

Lift Off

A selection of nanoscale processes is studied theoretically, with the aim of identifying themechanisms that could lead to selective carbon nanotube (CNT) growth. Only mechanisms relevant to catalytic chemical vapour deposition (CVD) are considered. The selected processes are analysed with classical molecular dynamics (MD) simulations and continuum modelling. The melting and pre-melting behaviour of supported nickel catalyst particles is investigated. Favourable epitaxy between a nanoparticle and the substrate is shown to significantly raise themelting point of the particle. It is also demonstrated that substrate binding can induce solid-solid transformations, whilst the epitaxy may even determine the orientation of individual crystal planes in supported catalysts. These findings suggest that the substrate crystal structure alone can potentially be used to manipulate the properties of catalyst particles and, hence, influence the structure of CNTs. The first attempt at modelling catalyst dewetting, a process where the catalyst unbinds from the inner walls of a nucleating nanotube, is presented. It is argued that understanding this process and gaining control over itmay lead to better selectivity in CNT growth. Two mutually exclusive dewetting mechanisms, namely cap lift-off and capillary withdrawal, are identified and then modelled as elastocapillary phenomena. The modelling yields an upper bound on the diameter of CNTs that can stem from a catalyst particle of a given size. It is also demonstrated that cap lift-off is sensitive to cap topology, suggesting that it may be possible to link catalyst characteristics to the structural properties of nucleating CNTs. However, a clear link to the chiral vector remains elusive. It is shown that particle size, as well as binding affinity, plays a critical role in capillary absorption and withdrawal of catalyst nanoparticles. This size dependence is explored in detail, revealing interesting ramifications to the statics and dynamics of capillary-driven flows at the nanoscale. The findings bear significant implications for our understanding of CNT growth from catalyst particles, whilst also suggesting new nanofluidic applications and methods for fabricating composite metal-CNT materials.

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Mechanisms in Carbon Nanotube Growth: Modelling and Molecular Dynamics Simulations

10.26686/wgtn.17009936 ◽

2021 ◽

Author(s):

◽

Dmitri Schebarchov

Keyword(s):

Molecular Dynamics ◽

Carbon Nanotube ◽

Supported Catalysts ◽

Critical Role ◽

Chemical Vapour ◽

Catalyst Particle ◽

Md Simulations ◽

Capillary Absorption ◽

Supported Nickel Catalyst ◽

Lift Off

A selection of nanoscale processes is studied theoretically, with the aim of identifying themechanisms that could lead to selective carbon nanotube (CNT) growth. Only mechanisms relevant to catalytic chemical vapour deposition (CVD) are considered. The selected processes are analysed with classical molecular dynamics (MD) simulations and continuum modelling. The melting and pre-melting behaviour of supported nickel catalyst particles is investigated. Favourable epitaxy between a nanoparticle and the substrate is shown to significantly raise themelting point of the particle. It is also demonstrated that substrate binding can induce solid-solid transformations, whilst the epitaxy may even determine the orientation of individual crystal planes in supported catalysts. These findings suggest that the substrate crystal structure alone can potentially be used to manipulate the properties of catalyst particles and, hence, influence the structure of CNTs. The first attempt at modelling catalyst dewetting, a process where the catalyst unbinds from the inner walls of a nucleating nanotube, is presented. It is argued that understanding this process and gaining control over itmay lead to better selectivity in CNT growth. Two mutually exclusive dewetting mechanisms, namely cap lift-off and capillary withdrawal, are identified and then modelled as elastocapillary phenomena. The modelling yields an upper bound on the diameter of CNTs that can stem from a catalyst particle of a given size. It is also demonstrated that cap lift-off is sensitive to cap topology, suggesting that it may be possible to link catalyst characteristics to the structural properties of nucleating CNTs. However, a clear link to the chiral vector remains elusive. It is shown that particle size, as well as binding affinity, plays a critical role in capillary absorption and withdrawal of catalyst nanoparticles. This size dependence is explored in detail, revealing interesting ramifications to the statics and dynamics of capillary-driven flows at the nanoscale. The findings bear significant implications for our understanding of CNT growth from catalyst particles, whilst also suggesting new nanofluidic applications and methods for fabricating composite metal-CNT materials.

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Mechanisms in Carbon Nanotube Growth: Modelling and Molecular Dynamics Simulations

10.26686/wgtn.17003134 ◽

2021 ◽

Author(s):

◽

Dmitri Schebarchov

Keyword(s):

Molecular Dynamics ◽

Carbon Nanotube ◽

Supported Catalysts ◽

Critical Role ◽

Chemical Vapour ◽

Catalyst Particle ◽

Md Simulations ◽

Capillary Absorption ◽

Supported Nickel Catalyst ◽

Lift Off

A selection of nanoscale processes is studied theoretically, with the aim of identifying themechanisms that could lead to selective carbon nanotube (CNT) growth. Only mechanisms relevant to catalytic chemical vapour deposition (CVD) are considered. The selected processes are analysed with classical molecular dynamics (MD) simulations and continuum modelling. The melting and pre-melting behaviour of supported nickel catalyst particles is investigated. Favourable epitaxy between a nanoparticle and the substrate is shown to significantly raise themelting point of the particle. It is also demonstrated that substrate binding can induce solid-solid transformations, whilst the epitaxy may even determine the orientation of individual crystal planes in supported catalysts. These findings suggest that the substrate crystal structure alone can potentially be used to manipulate the properties of catalyst particles and, hence, influence the structure of CNTs. The first attempt at modelling catalyst dewetting, a process where the catalyst unbinds from the inner walls of a nucleating nanotube, is presented. It is argued that understanding this process and gaining control over itmay lead to better selectivity in CNT growth. Two mutually exclusive dewetting mechanisms, namely cap lift-off and capillary withdrawal, are identified and then modelled as elastocapillary phenomena. The modelling yields an upper bound on the diameter of CNTs that can stem from a catalyst particle of a given size. It is also demonstrated that cap lift-off is sensitive to cap topology, suggesting that it may be possible to link catalyst characteristics to the structural properties of nucleating CNTs. However, a clear link to the chiral vector remains elusive. It is shown that particle size, as well as binding affinity, plays a critical role in capillary absorption and withdrawal of catalyst nanoparticles. This size dependence is explored in detail, revealing interesting ramifications to the statics and dynamics of capillary-driven flows at the nanoscale. The findings bear significant implications for our understanding of CNT growth from catalyst particles, whilst also suggesting new nanofluidic applications and methods for fabricating composite metal-CNT materials.

Download Full-text