Patents by Inventor Nai-Chang Yeh
Nai-Chang Yeh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11823895Abstract: A method of forming graphene on a flexible substrate includes providing a polymer substrate including a metal structure and providing a carbon source and a carrier gas. The method also includes subjecting the polymer substrate to a plasma enhanced chemical vapor deposition (PECVD) process and growing a graphene layer on the copper structure.Type: GrantFiled: October 13, 2021Date of Patent: November 21, 2023Assignees: California Institute of Technology, Industrial Technology Research InstituteInventors: Chen-Hsuan Lu, Chyi-Ming Leu, Nai-Chang Yeh, Chih-Cheng Lin, Chi-Fu Tseng
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Patent number: 11746018Abstract: A strain engineered material including a monolayer graphene sheet comprising an array of wrinkles induced by deformations in the graphene sheet, the deformations formed by a lattice of underlying nanostructures on a substrate. The lattice of nanostructures comprises rows of the nanostructures and each of the wrinkles comprise a ridge aligned on top of a different one of the rows and along an alignment direction defined by the rows. The deformations pattern a strain distribution in the graphene sheet that induces a periodically varying pseudo magnetic field distribution ranging between a positive value and a negative values. The periodically varying pseudo magnetic field distribution has field magnitude minima located parallel to and between the ridges and field magnitude maxima located near to and parallel to each of the ridges and can be designed for various valleytronic and spintronic device applications.Type: GrantFiled: May 7, 2021Date of Patent: September 5, 2023Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: Nai-Chang Yeh, Chen-Chih Hsu, Jiaqing Wang, Marcus L. Teague
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Publication number: 20230212743Abstract: A method of growing one or more graphene sheets on one or more regions of an optical fiber using plasma-enhanced chemical vapor deposition (PECVD) includes placing the optical fiber in a growth chamber, placing one or more carbon-containing precursors in the growth chamber, forming a reduced pressure in the growth chamber, and flowing methane gas and hydrogen gas into the growth chamber. The method also includes generating a plasma in the growth chamber, forming a gaseous carbon-containing precursor from the one or more carbon-containing precursors, exposing the one or more regions of the optical fiber to the methane gas, the hydrogen gas, the gaseous carbon-containing precursor, and the plasma, and forming the one or more graphene sheets on the one or more regions of the optical fiber.Type: ApplicationFiled: December 22, 2022Publication date: July 6, 2023Applicant: California Institute of TechnologyInventors: Deepan Kishore Kumar, Nai-Chang Yeh
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Publication number: 20230089278Abstract: Described are devices, such as light emitters, lasers, and switches, and methods, such as methods of generating photoluminescence and methods of fabricating electronic devices. Example devices and methods described include those comprising or employing optically active graphene, such as in the form of one or more layers of quasi-1D graphene nanomaterials or graphene nanostripes including one or more topological defects. Optically active graphene can emit photoluminescence upon exposure to photoexcitation and can also generate laser emission, optionally as a frequency comb. The optically active graphene can be patterned onto substrates according to the disclosed methods of fabricating electronic devices and is optionally useful for generating optical switches.Type: ApplicationFiled: September 22, 2022Publication date: March 23, 2023Applicant: California Institute of TechnologyInventors: Deepan Kishore Kumar, Ph.d, Nai-Chang Yeh
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Publication number: 20220281749Abstract: A strain engineered material including a monolayer graphene sheet comprising an array of wrinkles induced by deformations in the graphene sheet, the deformations formed by a lattice of underlying nanostructures on a substrate. The lattice of nanostructures comprises rows of the nanostructures and each of the wrinkles comprise a ridge aligned on top of a different one of the rows and along an alignment direction defined by the rows. The deformations pattern a strain distribution in the graphene sheet that induces a periodically varying pseudo magnetic field distribution ranging between a positive value and a negative values, The periodically varying pseudo magnetic field distribution has field magnitude minima located parallel to and between the ridges and field magnitude maxima located near to and parallel to each of the ridges and can be designed for various valleytronic and spintronic device applications.Type: ApplicationFiled: May 7, 2021Publication date: September 8, 2022Inventors: Nai-Chang Yeh, Chen-Chih Hsu, Jiaqing Wang, Marcus L. Teague
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Publication number: 20220115230Abstract: A method of forming graphene on a flexible substrate includes providing a polymer substrate including a metal structure and providing a carbon source and a carrier gas. The method also includes subjecting the polymer substrate to a plasma enhanced chemical vapor deposition (PECVD) process and growing a graphene layer on the copper structure.Type: ApplicationFiled: October 13, 2021Publication date: April 14, 2022Applicants: CALIFORNIA INSTITUTE OF TECHNOLOGY, Industrial Technology Research InstituteInventors: Chen-Hsuan Lu, Chyi-Ming Leu, Nai-Chang Yeh, Chih-Cheng Lin, Chi-Fu Tseng
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Patent number: 11111584Abstract: A method of forming vertical graphene nanostripes comprising one or several monolayers and characterized by a thickness normal to the one or several monolayers, a length orthogonal to the thickness, and a width orthogonal to the thickness includes providing a substrate, subjecting the substrate to a reduced pressure environment in a processing chamber, and providing methane gas and C6-containing precursor. The method also includes flowing the methane gas and the C6-containing precursor into the processing chamber, establishing a partial pressure ratio of the C6-containing precursor to methane gas in the processing chamber, and generating a plasma. The method further includes exposing at least a portion of the substrate to the methane gas, the C6-containing precursor, and the plasma and growing the vertical graphene nanostripes coupled to the at least a portion of the substrate, wherein the thickness of the vertical graphene nanostripes extends parallel to the substrate.Type: GrantFiled: October 21, 2019Date of Patent: September 7, 2021Assignee: California Institute of TechnologyInventors: Nai-Chang Yeh, Chen-Chih Hsu
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Patent number: 10837102Abstract: A method of forming graphene includes placing a substrate in a processing chamber and introducing a cleaning gas including hydrogen and nitrogen into the processing chamber. The method also includes introducing a carbon source into the processing chamber and initiating a microwave plasma in the processing chamber. The method further includes subjecting the substrate to a flow of the cleaning gas and the carbon source for a predetermined period of time to form the graphene.Type: GrantFiled: June 22, 2018Date of Patent: November 17, 2020Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: David A. Boyd, Nai-Chang Yeh
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Publication number: 20200325574Abstract: A method of growing a plurality of graphene sheets includes providing a substrate comprising silicon, placing the substrate in a growth chamber, and flowing a gaseous carbon containing precursor and a carrier gas into the growth chamber. A partial pressure ratio of the gaseous carbon containing precursor to the carrier gas is less than 5.5. The method also includes generating a CMOS compatible microwave plasma in the growth chamber. The CMOS compatible microwave plasma is characterized by a power density between 60 W/cm3 and 80 W/cm3. The method further includes subjecting the substrate to the microwave plasma and growing the plurality of graphene sheets to fully cover the substrate.Type: ApplicationFiled: April 13, 2020Publication date: October 15, 2020Inventors: Wei-Shiuan Tseng, Nai-Chang Yeh
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Publication number: 20200048769Abstract: A method of forming vertical graphene nanostripes comprising one or several monolayers and characterized by a thickness normal to the one or several monolayers, a length orthogonal to the thickness, and a width orthogonal to the thickness includes providing a substrate, subjecting the substrate to a reduced pressure environment in a processing chamber, and providing methane gas and C6-containing precursor. The method also includes flowing the methane gas and the C6-containing precursor into the processing chamber, establishing a partial pressure ratio of the C6-containing precursor to methane gas in the processing chamber, and generating a plasma. The method further includes exposing at least a portion of the substrate to the methane gas, the C6-containing precursor, and the plasma and growing the vertical graphene nanostripes coupled to the at least a portion of the substrate, wherein the thickness of the vertical graphene nanostripes extends parallel to the substrate.Type: ApplicationFiled: October 21, 2019Publication date: February 13, 2020Inventors: Nai-Chang Yeh, Chen-Chih Hsu
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Patent number: 10465291Abstract: A method of forming graphene nanostripes includes providing a substrate comprising at least one of copper foil or nickel foam and subjecting the substrate to a reduced pressure environment in a processing chamber. The method also includes providing methane gas and 1,2-dichlorobenzene (1,2-DCB) gas, flowing the methane gas and the 1,2-DCB into the processing chamber, and establishing a partial pressure ratio of 1,2-DCB gas to methane gas in the processing chamber. The partial pressure ratio is between 0 and 3. The method further includes generating a plasma, thereafter, exposing the at least a portion of the substrate to the methane gas, the 1,2-DCB gas, and the plasma, and growing the graphene nanostripes coupled to the at least a portion of the substrate.Type: GrantFiled: February 20, 2018Date of Patent: November 5, 2019Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: Nai-Chang Yeh, Chen-Chih Hsu
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Publication number: 20190093227Abstract: A method of forming graphene nanostripes includes providing a substrate comprising at least one of copper foil or nickel foam and subjecting the substrate to a reduced pressure environment in a processing chamber. The method also includes providing methane gas and 1,2-dichlorobenzene (1,2-DCB) gas, flowing the methane gas and the 1,2-DCB into the processing chamber, and establishing a partial pressure ratio of 1,2-DCB gas to methane gas in the processing chamber. The partial pressure ratio is between 0 and 3. The method further includes generating a plasma, thereafter, exposing the at least a portion of the substrate to the methane gas, the 1,2-DCB gas, and the plasma, and growing the graphene nanostripes coupled to the at least a portion of the substrate.Type: ApplicationFiled: February 20, 2018Publication date: March 28, 2019Applicant: California Institute of TechnologyInventors: Nai-Chang Yeh, Chen-Chih Hsu
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Publication number: 20190010604Abstract: A method of forming graphene includes placing a substrate in a processing chamber and introducing a cleaning gas including hydrogen and nitrogen into the processing chamber. The method also includes introducing a carbon source into the processing chamber and initiating a microwave plasma in the processing chamber. The method further includes subjecting the substrate to a flow of the cleaning gas and the carbon source for a predetermined period of time to form the graphene.Type: ApplicationFiled: June 22, 2018Publication date: January 10, 2019Inventors: David A. BOYD, Nai-Chang YEH
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Patent number: 10041168Abstract: A method of forming graphene includes placing a substrate in a processing chamber and introducing a cleaning gas including hydrogen and nitrogen into the processing chamber. The method also includes introducing a carbon source into the processing chamber and initiating a microwave plasma in the processing chamber. The method further includes subjecting the substrate to a flow of the cleaning gas and the carbon source for a predetermined period of time to form the graphene.Type: GrantFiled: January 10, 2014Date of Patent: August 7, 2018Assignee: California Institute of TechnologyInventors: David A. Boyd, Nai-Chang Yeh
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Publication number: 20150079342Abstract: A method of forming graphene includes placing a substrate in a processing chamber and introducing a cleaning gas including hydrogen and nitrogen into the processing chamber. The method also includes introducing a carbon source into the processing chamber and initiating a microwave plasma in the processing chamber. The method further includes subjecting the substrate to a flow of the cleaning gas and the carbon source for a predetermined period of time to form the graphene.Type: ApplicationFiled: January 10, 2014Publication date: March 19, 2015Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: David A. Boyd, Nai-Chang Yeh