Wai Ko Phones & Addresses
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Daly City, CA
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San Francisco, CA
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Santa Clara, CA
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Sunnyvale, CA
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San Jose, CA
Publications
Us Patents
Nanoneedle Plasmonic Photodetectors And Solar Cells
View pageUS Patent:
20110146771, Jun 23, 2011
Filed:
May 27, 2010
Appl. No.:
12/789026
Inventors:
Chih-Wei Chuang - Albany CA, US
Connie Chang-Hasnain - Palo Alto CA, US
Forrest Grant Sedgwick - Berkeley CA, US
Wai Son Ko - Berkeley CA, US
Connie Chang-Hasnain - Palo Alto CA, US
Forrest Grant Sedgwick - Berkeley CA, US
Wai Son Ko - Berkeley CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01L 31/06
H01L 31/0352
H01L 31/18
H01L 31/0352
H01L 31/18
US Classification:
136255, 257 14, 438 71, 257E31032, 977762, 977954
Abstract:
The present disclosure provides a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400 C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (μm) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6 to 9 tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.
Nanoneedle Plasmonic Photodetectors And Solar Cells
View pageUS Patent:
20130330875, Dec 12, 2013
Filed:
Jan 10, 2013
Appl. No.:
13/738215
Inventors:
The Regents of the University of California - , US
Connie Chang-Hasnain - Palo Alto CA, US
Wai Son Ko - Berkeley CA, US
Connie Chang-Hasnain - Palo Alto CA, US
Wai Son Ko - Berkeley CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01L 31/18
US Classification:
438 93, 977900, 977954
Abstract:
The present disclosure provides a method for a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400 C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (μm) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6 to 9 tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.
Nanopillar Optical Resonator
View pageUS Patent:
20140353712, Dec 4, 2014
Filed:
Jul 15, 2011
Appl. No.:
13/184019
Inventors:
Connie Chang-Hasnain - Palo Alto CA, US
Forrest Sedgwick - Berkeley CA, US
Roger Chen - Berkeley CA, US
Kar Wei Ng - Berkeley CA, US
Wai Son Ko - Menlo Park CA, US
Forrest Sedgwick - Berkeley CA, US
Roger Chen - Berkeley CA, US
Kar Wei Ng - Berkeley CA, US
Wai Son Ko - Menlo Park CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01S 5/10
H01L 33/24
H01L 33/00
H01L 33/32
H01L 33/26
H01S 5/30
H01L 33/30
H01L 33/24
H01L 33/00
H01L 33/32
H01L 33/26
H01S 5/30
H01L 33/30
US Classification:
257103, 438 39
Abstract:
Embodiments of a monolithically integrated optical resonator are disclosed. In one embodiment, the optical resonator is a nanopillar optical resonator that is formed directly on a substrate and promotes a helically-propagating cavity mode. The helically-propagating cavity mode results in significant reflection or, in some embodiments, total internal reflection at an interface of the nanopillar optical resonator and the substrate even if refractive indices of the nanopillar optical resonator and the substrate are the same or similar. As a result, strong optical feedback, and thus strong resonance, is provided in the nanopillar optical resonator.