Patents by Inventor David Z. Ting
David Z. Ting 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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Publication number: 20230114881Abstract: Disclosed herein is an infrared detector. The detector includes a plurality of pixels. Each pixel includes an n-type semiconductor top contact layer, a p-type semiconductor layer electrically connected to the n-type top contact layer to form a top p-n junction, a unipolar electron barrier electrically connected to the p-type semiconductor layer, a bottom absorber, and an n-type semiconductor bottom contact layer electrically connected to the bottom absorber. The unipolar electron barrier is positioned between the p-type semiconductor layer and the bottom absorber.Type: ApplicationFiled: October 7, 2022Publication date: April 13, 2023Applicant: California Institute of TechnologyInventors: David Z. Ting, Sam A. Keo, Arezou Khoshakhlagh, Alexander Soibel, Sarath D. Gunapala
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Patent number: 10872987Abstract: Barrier infrared detectors having structures configured to enhance the quantum efficiency, and methods of their manufacture are provided. In particular, device structures for constructing high-performance barrier infrared detectors using novel combinations of p-type and n-type absorber regions and contact regions are provided. The infrared detectors generally incorporate a “p+Bpnn+” structure. The detectors generally comprise, in sequence, a highly p-doped contact layer “p+”, an electron unipolar barrier “B”, a p-type absorber section “p”, and n-type absorber section “n”, and a highly n-doped contact layer “n+”.Type: GrantFiled: December 12, 2016Date of Patent: December 22, 2020Assignee: California Institute of TechnologyInventors: David Z. Ting, Alexander Soibel, Arezou Khoshakhlagh, Sarath D. Gunapala
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Publication number: 20190013427Abstract: Barrier infrared detectors having structures configured to enhance the quantum efficiency, and methods of their manufacture are provided. In particular, device structures for constructing high-performance barrier infrared detectors using novel combinations of p-type and n-type absorber regions and contact regions are provided. The infrared detectors generally incorporate a “p+Bpnn+” structure. The detectors generally comprise, in sequence, a highly p-doped contact layer “p+”, an electron unipolar barrier “B”, a p-type absorber section “p”, and n-type absorber section “n”, and a highly n-doped contact layer “n+”.Type: ApplicationFiled: December 12, 2016Publication date: January 10, 2019Applicant: California Institute of TechnologyInventors: David Z. Ting, Alexander Soibel, Arezou Khoshakhlagh, Sarath D. Gunapala
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Patent number: 9831372Abstract: Barrier infrared detectors configured to operate in the long-wave (LW) infrared regime are provided. The barrier infrared detector systems may be configured as pin, pbp, barrier and double heterostructrure infrared detectors incorporating optimized p-doped absorbers capable of taking advantage of high mobility (electron) minority carriers. The absorber may be a p-doped Ga-free InAs/InAsSb material. The p-doping may be accomplished by optimizing the Be doping levels used in the absorber material. The barrier infrared detectors may incorporate individual superlattice layers having narrower periodicity and optimization of Sb composition to achieve cutoff wavelengths of ˜10 ?m.Type: GrantFiled: May 13, 2016Date of Patent: November 28, 2017Assignee: California Institute of TechnologyInventors: Arezou Khoshakhlagh, David Z. Ting, Sarath D. Gunapala
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Patent number: 9799785Abstract: Dual-band barrier infrared detectors having structures configured to reduce spectral crosstalk between spectral bands and/or enhance quantum efficiency, and methods of their manufacture are provided. In particular, dual-band device structures are provided for constructing high-performance barrier infrared detectors having reduced crosstalk and/or enhance quantum efficiency using novel multi-segmented absorber regions. The novel absorber regions may comprise both p-type and n-type absorber sections. Utilizing such multi-segmented absorbers it is possible to construct any suitable barrier infrared detector having reduced crosstalk, including npBPN, nBPN, pBPN, npBN, npBP, pBN and nBP structures. The pBPN and pBN detector structures have high quantum efficiency and suppresses dark current, but has a smaller etch depth than conventional detectors and does not require a thick bottom contact layer.Type: GrantFiled: March 14, 2016Date of Patent: October 24, 2017Assignee: California Institute of TechnologyInventors: David Z. Ting, Alexander Soibel, Arezou Khoshakhlagh, Sarath Gunapala
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Patent number: 9647164Abstract: Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.Type: GrantFiled: October 16, 2014Date of Patent: May 9, 2017Assignee: California Institute of TechnologyInventors: David Z. Ting, Sarath D. Gunapala, Alexander Soibel, Jean Nguyen, Arezou Khoshakhlagh
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Publication number: 20160336476Abstract: Barrier infrared detectors configured to operate in the long-wave (LW) infrared regime are provided. The barrier infrared detector systems may be configured as pin, pbp, barrier and double heterostructrure infrared detectors incorporating optimized p-doped absorbers capable of taking advantage of high mobility (electron) minority carriers. The absorber may be a p-doped Ga-free InAs/InAsSb material. The p-doping may be accomplished by optimizing the Be doping levels used in the absorber material. The barrier infrared detectors may incorporate individual superlattice layers having narrower periodicity and optimization of Sb composition to achieve cutoff wavelengths of ˜10 ?m.Type: ApplicationFiled: May 13, 2016Publication date: November 17, 2016Inventors: Arezou Khoshakhlagh, David Z. Ting, Sarath D. Gunapala
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Patent number: 9466741Abstract: In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.Type: GrantFiled: December 16, 2009Date of Patent: October 11, 2016Assignee: California Institute of TechnologyInventors: Cory J. Hill, David Z. Ting, Sarath D. Gunapala
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Patent number: 9214581Abstract: Systems and methods of implementing barrier infrared detectors on lattice mismatched substrates are provided. The barrier infrared detector systems combine an active detector structure (e.g., contact/barrier/absorber pairs) with a non-lattice matched substrate through a multi-layered transitional structure that forms a virtual substrate that can be strain balanced with the detector structure. The transitional metamorphic layer may include one or both of at least one graded metamorphic buffer layer or interfacial misfit array (IMF). A further interfacial layer may be interposed within the transitional structure, in some embodiments this interfacial layer includes at least one layer of AlSb.Type: GrantFiled: February 11, 2014Date of Patent: December 15, 2015Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: Arezou Khoshakhlagh, David Z Ting, Sarath D. Gunapala, Cory J. Hill
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Publication number: 20150145091Abstract: Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.Type: ApplicationFiled: October 16, 2014Publication date: May 28, 2015Inventors: David Z. Ting, Sarath D. Gunapala, Alexander Soibel, Jean Nguyen, Arezou Khoshakhlagh
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Patent number: 8928029Abstract: Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.Type: GrantFiled: December 12, 2012Date of Patent: January 6, 2015Assignee: California Institute of TechnologyInventors: David Z. Ting, Sarath D. Gunapala, Alexander Soibel, Jean Nguyen, Arezou Khoshakhlagh
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Patent number: 8928036Abstract: A barrier infrared detector with absorber materials having selectable cutoff wavelengths and its method of manufacture is described. A GaInAsSb absorber layer may be grown on a GaSb substrate layer formed by mixing GaSb and InAsSb by an absorber mixing ratio. A GaAlAsSb barrier layer may then be grown on the barrier layer formed by mixing GaSb and AlSbAs by a barrier mixing ratio. The absorber mixing ratio may be selected to adjust a band gap of the absorber layer and thereby determine a cutoff wavelength for the barrier infrared detector. The absorber mixing ratio may vary along an absorber layer growth direction. Various contact layer architectures may be used. In addition, a top contact layer may be isolated into an array of elements electrically isolated as individual functional detectors that may be used in a detector array, imaging array, or focal plane array.Type: GrantFiled: September 25, 2009Date of Patent: January 6, 2015Assignee: California Institute of TechnologyInventors: David Z. Ting, Cory J. Hill, Alexander Seibel, Sumith Y. Bandara, Sarath D. Gunapala
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Publication number: 20140225064Abstract: Systems and methods of implementing barrier infrared detectors on lattice mismatched substrates are provided. The barrier infrared detector systems combine an active detector structure (e.g., contact/barrier/absorber pairs) with a non-lattice matched substrate through a multi-layered transitional structure that forms a virtual substrate that can be strain balanced with the detector structure. The transitional metamorphic layer may include one or both of at least one graded metamorphic buffer layer or interfacial misfit array (IMF). A further interfacial layer may be interposed within the transitional structure, in some embodiments this interfacial layer includes at least one layer of AlSb.Type: ApplicationFiled: February 11, 2014Publication date: August 14, 2014Applicant: California Institute of TechnologyInventors: Arezou Khoshakhlagh, David Z. Ting, Sarath D. Gunapala, Cory J. Hill
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Patent number: 8368051Abstract: An infrared detector having a hole barrier region adjacent to one side of an absorber region, an electron barrier region adjacent to the other side of the absorber region, and a semiconductor adjacent to the electron barrier.Type: GrantFiled: July 10, 2009Date of Patent: February 5, 2013Assignee: California Institute of TechnologyInventors: David Z. Ting, Sumith V. Bandara, Cory J. Hill, Sarath D. Gunapala
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Patent number: 8217480Abstract: A superlattice-based infrared absorber and the matching electron-blocking and hole-blocking unipolar barriers, absorbers and barriers with graded band gaps, high-performance infrared detectors, and methods of manufacturing such devices are provided herein. The infrared absorber material is made from a superlattice (periodic structure) where each period consists of two or more layers of InAs, InSb, InSbAs, or InGaAs. The layer widths and alloy compositions are chosen to yield the desired energy band gap, absorption strength, and strain balance for the particular application. Furthermore, the periodicity of the superlattice can be “chirped” (varied) to create a material with a graded or varying energy band gap.Type: GrantFiled: August 3, 2011Date of Patent: July 10, 2012Assignee: California Institute of TechnologyInventors: David Z. Ting, Arezou Khoshakhlagh, Alexander Soibel, Cory J. Hill, Sarath D. Gunapala
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Publication number: 20120145996Abstract: A superlattice-based infrared absorber and the matching electron-blocking and hole-blocking unipolar barriers, absorbers and barriers with graded band gaps, high-performance infrared detectors, and methods of manufacturing such devices are provided herein. The infrared absorber material is made from a superlattice (periodic structure) where each period consists of two or more layers of InAs, InSb, InSbAs, or InGaAs. The layer widths and alloy compositions are chosen to yield the desired energy band gap, absorption strength, and strain balance for the particular application. Furthermore, the periodicity of the superlattice can be “chirped” (varied) to create a material with a graded or varying energy band gap.Type: ApplicationFiled: August 3, 2011Publication date: June 14, 2012Applicant: California Institute of TechnologyInventors: David Z. Ting, Arezou Khoshakhlagh, Alexander Soibel, Cory J. Hill, Sarath D. Gunapala
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Publication number: 20110176577Abstract: A multi-waveband temperature sensor array, in which each superpixel (e.g., 2×2 pixel cell) operates at a distinct thermal infrared (IR) waveband (e.g. four wavebands) is disclosed. Using an example high spatial resolution, four-band thermal IR band photodetector array, accurate temperature measurements on the surface of an object can be made without prior knowledge of the object emissivity. The multiband photodetector may employ intersubband transition in III-V semiconductor-based quantum layered structures where each photodetector stack absorbs photons within the specified wavelength band while allowing the transmission of photons in other spectral bands, thus efficiently permitting multiband detection. This produces multiple, spectrally resolved images of a scene that are recorded simultaneously in a single snapshot of the FPA. From the multispectral images and calibration information about the system, computational algorithms are used to produce the surface temperature map of a target.Type: ApplicationFiled: December 8, 2009Publication date: July 21, 2011Applicant: California Institute of TechnologyInventors: Sumith V. Bandara, Sarath D. Gunapala, John K. Liu, Robert C. Stirbl, Daniel W. Wilson, David Z. Ting
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Publication number: 20100155777Abstract: In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.Type: ApplicationFiled: December 16, 2009Publication date: June 24, 2010Applicant: California Institute of TechnologyInventors: Cory J. Hill, David Z. Ting, Sarath D. Gunapala
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Patent number: 7737411Abstract: An nBn detector is described where for some embodiments the barrier layer has a concentration gradient, for some embodiments the absorption layer has a concentration gradient, and for some embodiments the absorption layer is a chirped strained layer super lattice. The use of a graded barrier or absorption layer, or the use of a chirped strained layer super lattice for the absorption layer, allows for design of the energy bands so that the valence band may be aligned across the device. Other embodiments are described and claimed.Type: GrantFiled: October 10, 2008Date of Patent: June 15, 2010Assignee: California Institute of TechnologyInventors: Sarath D. Gunapala, David Z. Ting, Cory J. Hill, Sumith V. Bandara
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Publication number: 20100072514Abstract: A barrier infrared detector with absorber materials having selectable cutoff wavelengths and its method of manufacture is described. A GaInAsSb absorber layer may be grown on a GaSb substrate layer formed by mixing GaSb and InAsSb by an absorber mixing ratio. A GaAlAsSb barrier layer may then be grown on the barrier layer formed by mixing GaSb and AlSbAs by a barrier mixing ratio. The absorber mixing ratio may be selected to adjust a band gap of the absorber layer and thereby determine a cutoff wavelength for the barrier infrared detector. The absorber mixing ratio may vary along an absorber layer growth direction. Various contact layer architectures may be used. In addition, a top contact layer may be isolated into an array of elements electrically isolated as individual functional detectors that may be used in a detector array, imaging array, or focal plane array.Type: ApplicationFiled: September 25, 2009Publication date: March 25, 2010Applicant: California Institute of TechnologyInventors: David Z. Ting, Cory J. Hill, Alexander Soibel, Sumith V. Bandara, Sarath D. Gunapala