[go: up one dir, main page]

WO2009154379A2 - Matériau composite organique/inorganique comportant des réseaux tridimensionnels de nanotubes de carbone, procédé de préparation du matériau composite organique/inorganique et dispositif électronique utilisant le matériau composite organique/inorganique - Google Patents

Matériau composite organique/inorganique comportant des réseaux tridimensionnels de nanotubes de carbone, procédé de préparation du matériau composite organique/inorganique et dispositif électronique utilisant le matériau composite organique/inorganique Download PDF

Info

Publication number
WO2009154379A2
WO2009154379A2 PCT/KR2009/003185 KR2009003185W WO2009154379A2 WO 2009154379 A2 WO2009154379 A2 WO 2009154379A2 KR 2009003185 W KR2009003185 W KR 2009003185W WO 2009154379 A2 WO2009154379 A2 WO 2009154379A2
Authority
WO
WIPO (PCT)
Prior art keywords
organic
inorganic composite
nanorods
nanoholes
carbon nanotubes
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/KR2009/003185
Other languages
English (en)
Other versions
WO2009154379A3 (fr
Inventor
Haiwon Lee
Tae-Jae Lee
Jung-Eun Seo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Industry University Cooperation Foundation IUCF HYU
Original Assignee
Industry University Cooperation Foundation IUCF HYU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020090015436A external-priority patent/KR101071218B1/ko
Application filed by Industry University Cooperation Foundation IUCF HYU filed Critical Industry University Cooperation Foundation IUCF HYU
Priority to US12/999,489 priority Critical patent/US9177745B2/en
Publication of WO2009154379A2 publication Critical patent/WO2009154379A2/fr
Publication of WO2009154379A3 publication Critical patent/WO2009154379A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C01B32/162—Preparation characterised by catalysts
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/20—Carbon compounds, e.g. carbon nanotubes or fullerenes
    • H10K85/221—Carbon nanotubes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/02—Single-walled nanotubes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/08—Aligned nanotubes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
    • C01P2004/13—Nanotubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02367—Substrates
    • H01L21/0237—Materials
    • H01L21/02373—Group 14 semiconducting materials
    • H01L21/02381—Silicon, silicon germanium, germanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02367—Substrates
    • H01L21/02428—Structure
    • H01L21/0243—Surface structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02521—Materials
    • H01L21/02524—Group 14 semiconducting materials
    • H01L21/02527—Carbon, e.g. diamond-like carbon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02587—Structure
    • H01L21/0259—Microstructure
    • H01L21/02606—Nanotubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02612—Formation types
    • H01L21/02617—Deposition types
    • H01L21/02636—Selective deposition, e.g. simultaneous growth of mono- and non-monocrystalline semiconductor materials
    • H01L21/02639—Preparation of substrate for selective deposition
    • H01L21/02645—Seed materials
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells

Definitions

  • the present invention relates to an organic/inorganic composite comprising three-dimensional carbon nanotube (CNT) networks. More specifically, the present invention relates to an organic/inorganic composite with increased surface area and enhanced electron transfer efficiency which comprises uniform high-density three- dimensional carbon nanotube networks, as well as a method for preparing the organic/inorganic composite and an electronic device using the organic/inorganic composite.
  • CNT carbon nanotube
  • Carbon nanotubes are allotropes of carbon that is one of the most abundant elements on the earth.
  • Carbon nanotubes are tubular structures in which carbon atoms are coupled to each other in a hexagonal honeycomb pattern and have an extremely small diameter in the nanometer range. Such carbon nanotubes exhibit characteristics of metals or semiconductors depending on their diameter and rolled- up shape.
  • Carbon nanotubes are currently being investigated to overcome the limited mechanical and electrical properties of existing materials.
  • Particularly, single-walled carbon nanotube (SWCNT) bridges suspended between two electrodes or templates or three-dimensional networks thereof can find direct applications in a variety of electronic devices, including field emission displays (FEDs), nanotube interconnectors and nanosensors, due to their excellent electrical properties, such as high current density and ballistic conductance.
  • FEDs field emission displays
  • nanotube interconnectors nanosensors
  • carbon nanotube networks can be synthesized by selectively forming metal catalyst particles on desired sites of the surface of a silicon (Si) or silica (SiO 2 ) substrate and growing carbon nanotubes in a two- or three-dimensional network on the metal catalyst particles.
  • Si silicon
  • SiO 2 silica
  • a metal catalyst used is rendered inactive when the silicon substrate is used, leading to a marked decrease in the density of the networks.
  • the vapor deposition technique by which Fe or Co as the metal catalyst is deposited on the pillars to form thin films, involves two processing steps of inclining the patterned substrate right and left to deposit the metal catalyst on the upper and side surfaces of the nanoscale pillars, inevitably resulting in poor processing efficiency. Further, a high aspect ratio of the pillars makes it difficult for the catalyst to be uniformly deposited on the lower end portions of the pillars, thus leading to a low density of the carbon nanotubes.
  • U.S. Patent No. 7,189,430 discloses a method for forming carbon nanotube networks without involving any additional catalyst deposition step.
  • oxide template structures are covered with a gold (Au) masking material and a mixture of xylene as a carbon source and ferrocene as a catalyst is directly used.
  • Au gold
  • the use of the masking material brings about a reduction in processing efficiency, and continuous supply of iron (Fe) present in the ferrocene increases the Fe concentration of the carbon nanotubes, eventually resulting in a decrease in the purity of the carbon nanotubes.
  • a technique is known in which catalyst particles are formed on nanoscale pillars by dipping and then carbon nanotube networks are formed using the catalyst particles.
  • this technique has a problem in that the catalyst particles may aggregate or a large amount of the catalyst particles may be separated off from the pillars during subsequent cleaning, resulting in a decrease in the density of the carbon nanotube networks.
  • an organic/inorganic composite comprising three-dimensional carbon nanotube networks that can be directly applied to an electronic device because the carbon nanotubes are directly formed on a silicon substrate and that can achieve enhanced electron transfer efficiency because the three-dimensional carbon nanotube networks are formed in high density on nanorods having a high aspect ratio or inside nanoholes having a high aspect ratio.
  • a second object of the present invention is to provide a method for preparing the organic/inorganic composite.
  • a third object of the present invention is to provide an electronic device using the organic/inorganic composite.
  • an organic/inorganic composite comprising a silicon (Si) substrate formed with nanorods or nanoholes and three-dimensional networks of carbon nanotubes (CNTs) grown horizontally in parallel and suspended between the adjacent nanorods or inside the nanoholes.
  • the number of the three-dimensional carbon nanotube networks per unit volume may be at least 1.5/ ⁇ m 3 .
  • the number of carbon nanotube bridges formed between the two adjacent nanorods per unit height of the nanorods or inside the nanoholes per unit depth of the nanoholes is at least 3/ ⁇ m.
  • the Fe-Mo catalyst solution may contain Fe(NO 3 ) 3 -9H 2 O and an aqueous solution of molybdenum (Mo).
  • Mo molybdenum
  • Fe-Mo catalyst solution is between 5: 1 and 0.5: 1.
  • sonication may be performed in the dipping step.
  • the method may further comprise, after step (c), annealing the substrate adsorbed by the catalysts and supplying ammonia (NH 3 ) or hydrogen (H 2 ) gas to the annealed substrate to reduce the metal catalysts.
  • the carbon source gas may be selected from the group consisting of methane, ethylene, acetylene, benzene, hexane, ethanol, methanol, propanol gases, and mixed gases thereof.
  • the nanorods have a height of 2 to 200 ⁇ m and an aspect ratio of 2 to 100 and are spaced apart from each other at intervals of 50 to 2,000 nm.
  • the nanoholes may have a height of 2 to 200 ⁇ m and an aspect ratio of 2 to 100 and may be spaced apart from each other at intervals of 50 to 2,000 nm.
  • At least ten carbon nanotube bridges may be connected between the two adjacent nanorods or are formed horizontally inside the nanoholes to form three-dimensional networks of the carbon nanotubes.
  • an electronic device that is fabricated using the organic/inorganic composite.
  • the electronic device may be selected from the group consisting of electron emission sources, field emission displays (FEDs), light- emitting devices, light-receiving devices, solar cells, fuel cells and sensors.
  • FEDs field emission displays
  • the carbon nanotubes may be single-walled carbon nanotubes.
  • the metal catalysts can be uniformly formed on the nanorods or inside the nanoholes, irrespective of the height of the nanorods or the depth of the nanoholes and the shape and aspect ratio of the nanoholes or nanoholes.
  • the carbon nanotubes grow in a three-dimensional network structure directly over the entire surface of the nanorods or the whole inner surface of the nanoholes and are directly connected to the base electrodes. With this configuration, the three-dimensional carbon nanotube networks are highly dense per unit volume, and the organic/inorganic composite is highly electrically conductive and has a large surface area. Therefore, the use of the organic/inorganic composite according to the present invention enables the fabrication of an electronic device with greatly improved efficiency.
  • FIG. 1 illustrates schematic diagrams for explaining a method for preparing an organic/inorganic composite according to an embodiment of the present invention.
  • FIG. 2 illustrates schematic diagrams for explaining a method for preparing an organic/inorganic composite according to another embodiment of the present invention.
  • FIG. 3 illustrates a schematic diagram of a solar cell according to an embodiment of the present invention.
  • FIG. 4 shows scanning electron microscopy (SEM) images of nanorods of Si wafers, which were formed in Examples 1 to 3.
  • FIG. 5 shows top views of SEM images of organic/inorganic composites, which were prepared in Examples 1 to 3, and an enlarged image of one of the SEM images.
  • FIG. 6 shows oblique views of SEM images of organic/inorganic composites, which were prepared in Examples 1 to 3, and an enlarged image of one of the SEM images.
  • FIG. 7 shows side views of SEM images of organic/inorganic composites, which were prepared in Examples 1 to 3, and an enlarged image of one of the SEM images.
  • FIG. 8 shows top views of SEM images of an organic/inorganic composite, which was prepared in Comparative Example 1 , taken at different magnifications.
  • FIG. 9 shows side views of SEM images of an organic/inorganic composite, which was prepared in Comparative Example 1, taken at different magnifications.
  • FIG. 10 shows top views of SEM images of an organic/inorganic composite, which was prepared in Comparative Example 2, taken at different magnifications.
  • FIG. 1 1 shows side views of SEM images of an organic/inorganic composite, which was prepared in Comparative Example 2, taken at different magnifications.
  • FIG. 12 shows transmission electron microscopy (TEM) images of junctions between Si nanorods and carbon nanotubes of an organic/inorganic composite, which was prepared in Example 1.
  • FIG. 13 shows an oblique view of a SEM image of an organic/inorganic composite, which was prepared in Example 4, and enlarged views of the SEM image.
  • TEM transmission electron microscopy
  • FIG. 14 is a graph showing the average numbers of three-dimensional carbon nanotube bridges formed between two adjacent nanorods of organic/inorganic composites, which were prepared in Examples 1 to 3, based on the SEM images of FIGS. 4 through 7.
  • FIG. 15 shows Raman spectra (514 nm) of three-dimensional carbon nanotube networks formed in Example 1.
  • FIG. 16 is a graph showing the photocurrent characteristics of solar cells fabricated in Example 5.
  • the present invention provides an organic/inorganic composite which comprises a silicon (Si) substrate formed with nanorods or nanoholes and three- dimensional networks of carbon nanotubes grown horizontally in parallel and suspended between the adjacent nanorods or inside the nanoholes.
  • the organic/inorganic composite of the present invention is characterized in that the number of the three-dimensional carbon nanotube networks per unit volume is at least 1.5/ ⁇ m and the number of carbon nanotube bridges formed between the two adjacent nanorods per unit height of the nanorods or inside the nanoholes per unit depth of the nanoholes is at least 3/ ⁇ m.
  • the carbon nanotubes are highly densely formed per unit volume in the organic/inorganic composite and are directly connected to the conductive substrate at ends thereof, resulting in improved conductivity of the organic/inorganic composite. Therefore, the organic/inorganic composite can be directly applied to a variety of electronic devices.
  • the present invention also provides a method for preparing an organic/inorganic composite, which comprises: (a) preparing a Fe-Mo catalyst solution; (b) treating a Si substrate formed with nanorods or nanoholes with piranha solution, UV-ozone or oxygen plasma to modify the surface of the Si substrate into Si-OH; (c) dipping the surface-modified substrate in the catalyst solution to adsorb the metal catalysts on the substrate; and (d) supplying a carbon source gas to the substrate adsorbed by the catalysts to produce carbon nanotubes in a three- dimensional network structure.
  • the method of the present invention is characterized in that the three-dimensional carbon nanotube networks can be uniformly formed in high density over the entire surface of the nanorods or the whole inner surface of the nanoholes.
  • the intervals between the adjacent nanorods or nanoholes may be in the range of 10 nni to several tens of ⁇ m, but are not limited to this range.
  • portions of the substrate defined by the adjacent nanoholes become nanorods in shape.
  • FIGS. 1 and 2 schematically illustrate two embodiments of the method for preparing an organic/inorganic composite according to the present invention.
  • an organic/inorganic composite may be prepared by (a) etching a silicon substrate to form a three-dimensional structure having nanoholes, (b) introducing metal catalyst particles on the etched substrate by solution dipping, and (c) supplying a carbon source gas to the substrate, on which the metal catalyst particles are introduced, to produce carbon nanotubes in a three-dimensional network bridge structure.
  • an organic/inorganic composite may be prepared by (a) etching a silicon substrate to form a three-dimensional structure having nanorods, (b) introducing metal catalyst particles on the etched substrate by solution dipping, and (c) supplying a carbon source gas to the substrate, on which the metal catalyst particles are introduced, to produce carbon nanotubes in a three-dimensional network bridge structure.
  • the silicon substrate can be etched by any suitable process known in the art. For example, the Bosch process may be used to etch the silicon substrate.
  • a direct growth process may also be used in which a catalyst is formed on the Si substrate and a Si source is supplied to grow Si nanorods directly on the Si substrate.
  • a substrate where the carbon nanotubes are to grow, should not be sintered together with the metal catalyst when heat is applied to grow the carbon nanotubes.
  • a silicon substrate is sintered together with Fe as a metal catalyst to form Fe x Si y during growth of carbon nanotubes. That is, the catalyst loses its catalytic activity for the growth of the carbon nanotubes, resulting in a decrease in the density of the grown carbon nanotubes.
  • the prior art uses silica (SiO 2 ) substrates rather than silicon substrates.
  • the surface of silica nanorods or nanoholes formed after etching is not electrically conductive because the silica per se is a nonconductor.
  • the catalysts are protected from inactivation to grow three-dimensional networks of carbon nanotubes in high density even at the lowest portions of the nanorods or the nanoholes.
  • the nanorods act as base electrodes. Since the carbon nanotubes are directly connected to the base electrodes, high conductivity of the organic/inorganic composite is achieved. It is believed that the reason why the Fe particles can be prevented from sintering despite the use of the silicon substrate is because the Mo acts as a barrier to the sintering.
  • the composition of the Fe-Mo catalyst solution is not particularly limited.
  • the Fe-Mo catalyst solution may contain Fe(NO 3 ) 3 -9H 2 O and an aqueous solution of molybdenum (Mo).
  • Mo molybdenum
  • the nanorods or nanoholes of the silicon substrate can be formed by any suitable method commonly used in the art, such as electrochemical etching, photolithography or direct synthesis.
  • the height of the nanorods, the depth of the nanoholes, and the shape and intervals of the nanorods or the nanoholes is no particular restriction.
  • the nanorods are higher 200 ⁇ m or the nanoholes are deeper than 200 ⁇ m, there is the risk that carbon nanotubes may not be uniformly formed at the lower portions of the nanorods or nanoholes. If the adjacent nanorods or nanoholes are spaced apart from each other at intervals of less than 50 nm, they are too close to each other to produce carbon nanotubes. If the adjacent nanorods or nanoholes are spaced apart from each other at intervals of more than 2,000 nm, there is the risk that carbon nanotube bridge networks may be difficult to form. There is a need to limit the aspect ratio of the nanorods in order to increase the number of three- dimensional carbon nanotube networks per unit space. If the nanorods have an aspect ratio lower than 2 or higher than 100, there is the risk that the density of carbon nanotubes may decrease.
  • the patterned silicon substrate is cleaned with suitable solvents, such as acetone, ethanol and deionized water, and is treated with piranha solution, UV-ozone or oxygen plasma to modify the surface of the Si substrate into Si-OH.
  • suitable solvents such as acetone, ethanol and deionized water
  • piranha solution UV-ozone or oxygen plasma to modify the surface of the Si substrate into Si-OH.
  • the -OH groups interact with the metal catalysts or the catalyst ions to prevent the metal catalysts from being separated from the surface of the nanorods or nanoholes in the subsequent cleaning step.
  • the piranha solution is a mixture of sulfuric acid and hydrogen peroxide.
  • the molar concentration ratio of Fe to Mo in the Fe-Mo catalyst solution is between 5 : 1 and 0.5: 1. If the Mo concentration is less than the lower limit, Fe is sintered to lose its activity, resulting in a decrease in the density of carbon nanotubes. Meanwhile, if the Mo concentration is greater than the upper limit, the Mo cannot function as a seed for the growth of carbon nanotubes, there is the risk that the density of the carbon nanotubes may decrease.
  • the Fe-Mo catalyst solution may be a mixture of an ethanolic solution of Fe(NOs) 3 -9H 2 O and an aqueous solution of molybdenum
  • sonication may be performed in a state in which the surface-modified Si substrate is dipped in the catalyst solution. This sonication permits uniform adsorption of the metal catalysts on the Si substrate.
  • the method of the present invention may further comprise annealing the substrate adsorbed by the metal catalysts in a reactor and feeding NH 3 or H 2 gas into the reactor to reduce the metal catalysts.
  • the annealing is conducted under vacuum or an atmosphere containing oxygen. Typically, the annealing may be conducted at about 300 to about 500 0 C for about 10 to about 60 min.
  • the reason for the annealing is to remove organic/inorganic chemical substances attached to the metal catalysts and the substrate and to oxidize the surface of the catalyst particles. This oxidization inhibits the metal catalysts from migrating at high temperatures and prevents the metal catalysts from aggregation.
  • the metal catalysts are not sufficiently annealed at a temperature lower than 300 0 C, while excessive thermal energy is created at a temperature higher than 500 0 C to activate the thermal motion of the metal catalysts, posing the risk that the metal catalysts may aggregate.
  • the oxygen-containing atmosphere for annealing is advantageous in removing organic chemical substances but increases the risk that the surface of the silicon substrate may be oxidized. Despite this risk, short annealing time minimizes the amount of the silicon oxidized to a negligible level.
  • H 2 or NH 3 gas is fed into the reactor to reduce the metal catalyst oxides.
  • the reactor is heated to about 700 to about 900 0 C while reducing the internal pressure to about 10 "2 torr or lower.
  • H 2 or NH 3 gas can be fed into the reactor when the reactor is stabilized at about 800 0 C.
  • the gas may be fed into the reactor while increasing the reactor temperature.
  • the internal pressure and temperature of the reactor are not limited to the ranges defined above.
  • a carbon source gas is fed into the reactor to produce carbon nanotubes.
  • Any suitable carbon source gas may be used without any limitation.
  • the carbon source gas can be selected from the group consisting of methane, ethylene, acetylene, benzene, hexane, ethanol, methanol, propanol gases, and mixed gases thereof.
  • the carbon nanotubes are typically single-walled carbon nanotubes, but are not limited thereto.
  • the carbon nanotubes may be multi-walled carbon nanotubes. Multi- walled carbon nanotubes are advantageous because of their conductivity higher than that of single-walled carbon nanotubes.
  • the number of the carbon nanotube bridges connected between the two adjacent nanorods of the organic/inorganic composite is preferably at least 10. As the number of the carbon nanotubes per unit space increases, the electrical conductivity and surface area of the organic/inorganic composite increase. Therefore, the use of the organic/inorganic composite enables the fabrication of an electronic device with improved efficiency.
  • the electronic device can be selected from the group consisting of electron emission sources, field emission displays (FEDs), light-emitting devices, light- receiving devices, solar cells, fuel cells and sensors.
  • FEDs field emission displays
  • light-emitting devices light-emitting devices
  • light- receiving devices solar cells
  • fuel cells fuel cells and sensors.
  • FIG. 3 illustrates a schematic diagram of a solar cell fabricated using the organic/inorganic composite in accordance with an embodiment of the present invention.
  • the solar cell is a kind of dye-sensitized solar cell.
  • the solar cell comprises an n-type silicon substrate disposed at the bottom thereof.
  • the three- dimensional carbon nanotube networks of the organic/inorganic composite according to the present invention are formed on the silicon substrate and CdSe quantum dots as inorganic compounds are adsorbed on the three-dimensional carbon nanotube networks.
  • IVI 3 " is used as an electrolyte.
  • the F plays a role in providing electrons to the CdSe molecules and the I 3 " , which is an oxidized form of I " , receives the electrons arrived at a counter electrode and is again reduced to I " .
  • Spacers are disposed at right and left sides of the electrolyte layer.
  • a platinum (Pt) electrode and ITO glass are sequentially disposed on the electrolyte layer.
  • n-type Si wafer was etched by common photolithography and the Bosch process to form nanorods having a height of 2 ⁇ m and a diameter of about 1 ⁇ m.
  • the nanorods were spaced apart from each other at intervals of 1 ⁇ m.
  • the etched Si wafer was cleaned with acetone, ethanol and deionized water, treated with piranha solution for 30 min to modify the surface of the Si wafer into Si-OH, and cleaned with deionized water.
  • An ethanolic solution of Fe(NO 3 ) 3 -9H 2 O (Junsei, Japan) was mixed with an aqueous solution of molybdenum (ICP/DCP standard solution, 10,000 ⁇ g/mL Mo in H 2 O, Aldrich) to prepare a catalyst solution.
  • the molar concentration ratio of Fe to Mo in the catalyst solution was adjusted to 4:1.
  • the surface-modified Si wafer was dipped in the catalyst solution to uniformly adsorb the catalysts over the entire surfaces of the wafer and the nanorods, cleaned with ethanol, and mounted in a horizontal quartz tube reactor.
  • the Si wafer adsorbed by the catalysts was annealed in air at 400 0 C for 30 min.
  • the reactor was heated to 800 0 C while maintaining the internal pressure at 1.0 x 10 "2 Torr or less. Then, the reactor was stabilized at a temperature of 800 0 C. NH 3 gas was fed into the reactor at 300 seem for 10 min to reduce the metal oxide catalysts to their pure metals. C 2 H 2 as a carbon source gas was fed into the reactor at 20 seem for 10 min to form three-dimensional networks of single-walled carbon nanotubes. At that time, the internal pressure of the reactor was maintained at 3.3 x 10 "1 Torr.
  • Three-dimensional networks of single-walled carbon nanotubes were formed in the same manner as in Example 1, except that the nanorods had a height of 5 ⁇ m and a diameter of about 0.75 ⁇ m and were spaced apart from each other at intervals of 1.25 ⁇ m.
  • Three-dimensional networks of single-walled carbon nanotubes were formed in the same manner as in Example 1, except that the nanorods had a height of 7 ⁇ m and a diameter of about 1.3 ⁇ m and were spaced apart from each other at intervals of 1.3 ⁇ m.
  • An n-type Si wafer was dipped in a mixed solvent of HF and ethanol, followed by electrochemical etching to form nanoholes having a depth of 40 ⁇ m and a diameter of about 200-1,000 nm. Then, the etched Si wafer was cleaned with acetone, ethanol and deionized water, treated with piranha solution for 30 min to modify the surface of the Si wafer into Si-OH, and cleaned with deionized water.
  • An ethanolic solution of Fe(NO 3 ) 3 -9H 2 O (Junsei, Japan) was mixed with an aqueous solution of molybdenum (ICP/DCP standard solution, 10,000 ⁇ g/mL Mo in H 2 O, Aldrich) to prepare a catalyst solution.
  • the molar concentration ratio of Fe to Mo in the catalyst solution was adjusted to 5 : 1.
  • the surface-modified Si wafer was dipped in the catalyst solution, followed by sonication to uniformly adsorb the catalysts over the entire surfaces of the wafer and the nanoholes, cleaned with ethanol, and mounted in a horizontal quartz tube reactor.
  • the Si wafer adsorbed by the catalysts was annealed in air at 400 0 C for 30 min.
  • the reactor was heated to 800 0 C while maintaining the internal pressure at 1.0 x 10 "2 Torr or less. Then, the reactor was stabilized at a temperature of 800 0 C.
  • NH 3 gas was fed into the reactor at 300 seem for 10 min to reduce the metal oxide catalysts to their pure metals.
  • C 2 H 2 as a carbon source gas was fed into the reactor at 20 seem for 10 min to form three-dimensional networks of single-walled carbon nanotubes. At that time, the internal pressure of the reactor was maintained at 3.3 x 10 "1 Torr.
  • n-type Si wafer was etched by common photolithography and the Bosch process to form nanorods having a height of 2 ⁇ m and a diameter of about 1 ⁇ m.
  • the nanorods were spaced apart from each other at intervals of 1 ⁇ m.
  • the etched Si wafer was cleaned with acetone, ethanol and deionized water, treated with piranha solution for 30 min to modify the surface of the Si wafer into Si-OH groups, and cleaned with deionized water.
  • An aqueous solution of cobalt (ICP/DCP standard solution, 9,923 PPM of Co in 0.6 wt.% HNO 3 , Aldrich) was mixed with an aqueous solution of molybdenum (ICP/DCP standard solution, 10,000 ⁇ g/mL Mo in H 2 O, Aldrich) to prepare a catalyst solution.
  • the molar concentration ratio of Co to Mo in the catalyst solution was adjusted to 4: 1.
  • the surface-modified Si wafer was dipped in the catalyst solution to uniformly adsorb the catalysts over the entire surfaces of the wafer and the nanorods, cleaned with ethanol, and mounted in a horizontal quartz tube reactor.
  • the Si wafer adsorbed by the catalysts was annealed in air at 400°C for 30 min.
  • the reactor was heated to 800 0 C while maintaining the internal pressure at 1.0 x 10 "2 Torr or less. Then, the reactor was stabilized at a temperature of 800 0 C. NH 3 gas was fed into the reactor at 300 seem for 10 min to reduce the metal oxide catalysts to their pure metals. C 2 H 2 as a carbon source gas was fed into the reactor at 20 seem for 10 min to form three- dimensional networks of single-walled carbon nanotubes. At that time, the internal pressure of the reactor was maintained at 3.3 x 10 "1 Torr.
  • Comparative Example 2 Carbon nanotube networks were formed in the same manner as in Comparative Example 1 , except that (C 2 H 3 O 2 ) 2 Co (Aldrich) was used instead of the aqueous solution of cobalt.
  • Example 5-(l) The surface-modified silicon electrode produced in Example 5-(l) was dipped in the solution of the surface-modified quantum dots, which was prepared in Example 5-(2), for one day to apply the CdSe quantum dots to the surface of the carbon nanotubes.
  • Test Example 2 Measurements of SEM and TEM images of three-dimensional carbon nanotube networks
  • FIGS. 5, 6 and 7 Top views, oblique views and side views of SEM images of the organic/inorganic composites prepared in Examples 1 -3 are shown in FIGS. 5, 6 and 7, respectively. An enlarged image of one of the SEM images is shown in each of FIGS. 5, 6 and 7.
  • Top views and side views of SEM images of the organic/inorganic composite prepared in Comparative Example 1 were taken at different magnifications (FIGS. 8 and 9).
  • Top views and side views of SEM images of the organic/inorganic composite prepared in Comparative Example 2 were taken at different magnifications (FIGS. 10 and 1 1).
  • the three-dimensional carbon nanotube networks were very uniformly formed between the lowest portions of the nanorods.
  • FIGS. 8 through 1 1 show that few carbon nanotube networks were formed or the carbon nanotube networks were formed at a very low density between the adjacent nanorods of the organic/inorganic composites prepared in Comparative Examples 1 and 2. From these observations, it can be known that the use of the Fe- Mo catalyst solution contributed to the formation of three-dimensional carbon nanotube networks in high density.
  • TEM transmission electron microscopy
  • FIG. 13 shows an oblique view of a SEM image of the organic/inorganic composite prepared in Example 4 and enlarged views of the SEM image.
  • the three-dimensional carbon nanotube networks were very uniformly formed at the surface of the nanohole (3b) as well as inside the nanoholes (3c and 3d).
  • Test Example 4 Determinations of average numbers of three-dimensional carbon nanotube bridges between the nanorods
  • the numbers of the three-dimensional carbon nanotube bridges formed between the two adjacent nanorods of the organic/inorganic composites prepared in Examples 1-3 were counted based on the corresponding SEM images, and then were averaged. The results are shown in FIG. 14.
  • the average numbers of the three- dimensional carbon nanotube bridges determined in Examples 1 -3 were 1 1 , 17 and 21, respectively. That is, the average number of the carbon nanotube bridges formed between the two adjacent nanorods tended to increase with increasing height of the nanorods.
  • FIG. 15 shows Raman spectra (514 nm) of the three-dimensional carbon nanotube networks formed in Example 1.
  • RBMs are observed at about 100-300 cm ' 1 , weak
  • Performance test of the solar cells The photocurrent characteristics of the solar cells fabricated in Example 5 were measured and the results are shown in FIG. 16.
  • White light 100 mW/cm 2 : l Sun
  • a photocurrent density of 1- 1.5 ⁇ A/cm 2 was measured in the solar cell using the substrate formed with the 2 ⁇ m high nanorods
  • a photocurrent density of 2.2-3 ⁇ A/cm 2 in the solar cell using the substrate formed with the 5 ⁇ m high nanorods a photocurrent density of 4.2-5.5 ⁇ A/cm 2 in the solar cell using the substrate formed with the 7 ⁇ m high nanorods.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Organic Chemistry (AREA)
  • Composite Materials (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

L'invention concerne un matériau composite organique/inorganique. Le matériau composite organique/inorganique comporte un substrat de silicium (Si) formé avec des nanotiges ou des nanotrous et des réseaux tridimensionnels de nanotubes de carbone (CNT) développés à l'horizontal en parallèle et mis en suspension entre les nanotiges adjacentes ou à l'intérieur des nanotrous. Dans le matériau composite organique/inorganique, des catalyseurs métalliques peuvent se former uniformément sur les nanotiges ou à l'intérieur des nanotrous, indépendamment de la hauteur des nanotiges ou de la profondeur des nanotrous et de la forme et du rapport largeur/hauteur des nanotiges ou des nanotrous. De plus, les nanotubes de carbone se développent dans une structure de réseau tridimensionnel directement sur la surface complète des nanotiges ou sur la surface interne entière des nanotrous et sont directement reliés aux électrodes de base. Avec cette configuration, les réseaux tridimensionnels de nanotubes de carbone sont très denses par unité de volume et le matériau composite organique/inorganique est très conducteur de l'électricité et possède une grande surface spécifique. Par conséquent, l'utilisation du matériau composite organique/inorganique permet la fabrication d'un dispositif électronique avec une efficacité très améliorée. L'invention concerne en outre un procédé de préparation du matériau composite organique/inorganique et un dispositif électronique préparé en utilisant le matériau composite organique/inorganique.
PCT/KR2009/003185 2008-06-19 2009-06-15 Matériau composite organique/inorganique comportant des réseaux tridimensionnels de nanotubes de carbone, procédé de préparation du matériau composite organique/inorganique et dispositif électronique utilisant le matériau composite organique/inorganique Ceased WO2009154379A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/999,489 US9177745B2 (en) 2008-06-19 2009-06-15 Organic/inorganic composite comprising three-dimensional carbon nanotube networks, method for preparing the organic/inorganic composite and electronic device using the organic/inorganic composite

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2008-0057996 2008-06-19
KR20080057996 2008-06-19
KR1020090015436A KR101071218B1 (ko) 2008-06-19 2009-02-24 탄소나노튜브 3차원 네트워크를 포함하는 유무기 복합체, 그 제조방법 및 이를 이용하여 제조된 전자소자
KR10-2009-0015436 2009-02-24

Publications (2)

Publication Number Publication Date
WO2009154379A2 true WO2009154379A2 (fr) 2009-12-23
WO2009154379A3 WO2009154379A3 (fr) 2010-04-08

Family

ID=41434540

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2009/003185 Ceased WO2009154379A2 (fr) 2008-06-19 2009-06-15 Matériau composite organique/inorganique comportant des réseaux tridimensionnels de nanotubes de carbone, procédé de préparation du matériau composite organique/inorganique et dispositif électronique utilisant le matériau composite organique/inorganique

Country Status (1)

Country Link
WO (1) WO2009154379A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102010597A (zh) * 2010-09-26 2011-04-13 南京大学 一种二维纳米阵列管道制备方法
CN102092675A (zh) * 2011-01-14 2011-06-15 中国科学院物理研究所 一种自掩模单结多端三维纳米结构的制备方法
CN109399612A (zh) * 2018-10-30 2019-03-01 国家纳米科学中心 一种悬空碳纳米管阵列及其制备方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6918284B2 (en) * 2003-03-24 2005-07-19 The United States Of America As Represented By The Secretary Of The Navy Interconnected networks of single-walled carbon nanotubes
US20070237681A1 (en) * 2005-09-30 2007-10-11 Paul Boyle Nanostructures containing inorganic nanotubes and methods of their synthesis and use

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102010597A (zh) * 2010-09-26 2011-04-13 南京大学 一种二维纳米阵列管道制备方法
CN102092675A (zh) * 2011-01-14 2011-06-15 中国科学院物理研究所 一种自掩模单结多端三维纳米结构的制备方法
CN109399612A (zh) * 2018-10-30 2019-03-01 国家纳米科学中心 一种悬空碳纳米管阵列及其制备方法
CN109399612B (zh) * 2018-10-30 2020-08-21 国家纳米科学中心 一种悬空碳纳米管阵列及其制备方法

Also Published As

Publication number Publication date
WO2009154379A3 (fr) 2010-04-08

Similar Documents

Publication Publication Date Title
US9177745B2 (en) Organic/inorganic composite comprising three-dimensional carbon nanotube networks, method for preparing the organic/inorganic composite and electronic device using the organic/inorganic composite
JP3804594B2 (ja) 触媒担持基板およびそれを用いたカーボンナノチューブの成長方法ならびにカーボンナノチューブを用いたトランジスタ
EP2543632B1 (fr) Méthode de production d'un agrégat de nanotubes de carbone alignés
CN103518238B (zh) 碳纳米管复合电极及其制造方法
US7618300B2 (en) Method of synthesizing small-diameter carbon nanotubes with electron field emission properties
JP2005075725A (ja) カーボンナノチューブ構造体及びその製造方法とそれを応用した電界放出素子及び表示装置
CN101508421B (zh) 用于场电子发射器的碳纳米纤维/碳纳米管异质纳米阵列及其制备技术
WO2011016616A2 (fr) Nanocomposite carboné de structure innovante et procédé pour son façonnage
KR101105473B1 (ko) 신규한 구조의 탄소계 나노복합체 및 이의 제조방법
Huo et al. Synthesis and field emission properties of rutile TiO2 nanowires arrays grown directly on a Ti metal self-source substrate
EP2305601B1 (fr) Composite nanotubes-nanocornets et leur procédé de fabrication
US20090200912A1 (en) Methods for Growing Carbon Nanotubes on Single Crystal Substrates
Shrestha et al. Preparation and field emission properties of Er-decorated multiwalled carbon nanotubes
KR101954381B1 (ko) SiNW 어레이 상에 수직 정렬된 CNTs의 무촉매 합성방법
Huang et al. SnO 2 nanorod arrays: low temperature growth, surface modification and field emission properties
KR101425376B1 (ko) 고분자 기반의 대면적 탄소 나노그물 및 그 제조방법
JP2003277029A (ja) カーボンナノチューブ及びその製造方法
KR20060042144A (ko) 금속 산화물 나노구조체들을 포함하는 소자 및 그 나노구조체들의 제조방법
WO2009154379A2 (fr) Matériau composite organique/inorganique comportant des réseaux tridimensionnels de nanotubes de carbone, procédé de préparation du matériau composite organique/inorganique et dispositif électronique utilisant le matériau composite organique/inorganique
KR20060002476A (ko) 탄소나노튜브 제조용 촉매 베이스의 제조 방법 및 이를이용한 탄소나노튜브 제조 방법
Zou et al. Fabrication, optoelectronic and photocatalytic properties of some composite oxide nanostructures
Hatakeyama et al. Plasma-synthesized single-walled carbon nanotubes and their applications
KR20160136045A (ko) 정렬된 담형태의 탄소나노튜브 구조체, 그 제조방법 및 이를 이용하여 제조된 전자소자
KR100899806B1 (ko) 탄소나노튜브-무기산화물 나노입자 복합체의 제조방법
KR100335383B1 (ko) 탄소 나노튜브의 제조방법

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09766804

Country of ref document: EP

Kind code of ref document: A2

WWE Wipo information: entry into national phase

Ref document number: 12999489

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09766804

Country of ref document: EP

Kind code of ref document: A2