Lawrence Livermore National Security, LLC

University of California

Other

US Government As Represented by the Secretary of the Army

University of Illinois

Bae Systems Land & Armaments L.p.

Socal Simulations, LLC

Adam M Conway

Lars F Voss

Rebecca J Nikolic

Qinghui Shao

Mihail Bora

Sara Elizabeth Harrison

Stephen Anthony Payne

Robert T Graff

Art J Nelson

Paulius Vytautas Grivickas

Erik Lars Swanberg, Jr

David Lawrence Hall

Chin Li Cheung

Victor V Khitrov

Tammy Chang

Catherine E Reinhardt

Daniel Heineck

Joshua D Kuntz

Stephen E Sampayan

Srabanti Chowdhury

George James Caporaso

Peter M Asbeck

Charles E Hunt

Hoang Tan Nguyen

John Edward Heebner

Michael Charles Rushford

Mark S Rader

Clint Frye

Steve Hawkins

Ishwara B Bhat

Hadong Kim

Joseph Devin Schneider

Caitlin Anne Chapin

Benjamin J Fasenfest

Cedric Rocha Leao

Sangtae Park

Devin Joseph Funaro

Luis M Hernandez

John Berns Lancaster

Mushtaq A Dar

Karen Marie Dowling

Patrick R Beck

Kexin Li

Shaloo Rakheja

Philip Datte

Clement Antoine Trosseille

Tzu Fang Wang

A product includes an elongated carbon-containing pillar having a bottom and a tip opposite the bottom. The width of the pillar measured 1 nm below the tip is less than 700 nm. A method includes masking a carbon-containing single crystal for defining masked regions and unmasked regions on the single crystal. The method also includes performing a plasma etch for removing portions of the unmasked regions of the single crystal, thereby defining a pillar in each unmasked region, and performing a chemical etch on the pillars at a temperature between 1200° C. and 1600° C. for selectively reducing a width of each pillar.

Silicon carbide nanoneedles and fabrication thereof

An apparatus includes at least one vertical transistor, where the at least one vertical transistor includes: a substrate including a first semiconductor material, an array of three dimensional (3D) structures above the substrate, a sidewall heterojunction layer positioned on at least one vertical sidewall of each 3D structure, and an isolation region positioned between the 3D structures. Each 3D structure includes the first semiconductor material. The sidewall heterojunction layer includes a second semiconductor material, where the first and second semiconductor material have different bandgaps.

Three dimensional vertically structured electronic devices

A high-voltage switch is adapted for use as a medium-voltage direct current circuit breaker, which provides a low-cost, small-footprint device to mitigate system faults. In one example, a method for operating a wideband optical device includes illuminating the wide bandgap optical device with a light within a first range of wavelengths and a first average intensity, allowing a current to propagate therethrough without substantial absorption of the current, illuminating the wide bandgap optical device with light within the first range of wavelengths and a second average intensity that is lower than the first average intensity to allow a sustained current flow though the wide bandgap optical device, and illuminating the wide bandgap optical device with light within a second range of wavelengths to stop or substantially restrict propagation of the current through the wide gap material.

Wide bandgap optical switch circuit breaker for controlling propagation of current therethrough a wide bandgap optical device

Devices, systems and methods for solid-state X-ray detection with high temporal resolution are described. An example method includes receiving an X-ray pulse in a semiconductor chip resulting in an electron cloud being formed in the semiconductor chip, applying a first set of voltages across a first plurality of drift cathode strips on a first side of the semiconductor chip and a second plurality of drift cathode strips on a second side of the semiconductor chip, applying a second set of voltages to across the first and the second plurality of drift cathode strips to form an electric field having a linear profile to cause the electron cloud to drift along the middle of the semiconductor chip, and activating a counter cathode on the second side and one or more readout anodes on the first side to collect the electron cloud after spreading in the middle section of the semiconductor chip.

High temporal resolution solid-state X-ray detection system

A high-voltage switch, whose operation leverages the speed of electrons to generate the 'on' time of the pulse in combination with the speed of light to generate the “off” time of the pulse, is described. In one example, the high-voltage switch includes a first electrode, a second electrode spaced apart from the first electrode, a region of non-absorbing material occupying a portion of the space between the first and second electrodes and allowing a laser pulse to propagate therethrough without substantial absorption, and a region of absorbing material occupying another portion of the space and producing a charged particle cloud upon receiving the laser pulse. The high-voltage switch remains “on” upon the charged particle cloud reaching an electrode and until it has been collected by the electrode, and where the high-voltage switch remains “off” subsequent to the collection and until another generated charged particle cloud reaches the electrode.

High-power electrically tunable switch

A photoconductive switch that uses materials that support negative differential mobility, whose operation leverages the pulse compression of a charge could to generate the 'on' time of the pulse in combination with the speed of light to generate the 'off' time of the pulse, is described. In one example, a method of operating a photoconductive switch, which includes two electrodes and a light absorbing material positioned therebetween, includes selecting a value for one or more parameters comprising a voltage for generation of an electric field, a spot size of a laser pulse, a temporal pulse width of the laser pulse, or an intensity of the laser pulse, wherein the selected value(s) for the one or more parameters enable the switch to operate in a region where the light absorbing material exhibits negative differential mobility, and illuminating the light absorbing material with the laser pulse to generate a charge cloud within the light absorbing material.

Pulse compression photoconductive semiconductor switches

Power amplifier apparatuses and techniques for optimizing the design of power amplifiers are disclosed. In one aspect, a method for optimizing a power amplifier includes selecting a circuit topology for the power amplifier. The circuit topology includes one or more photoconductive switches and an impedance matching network including one or more parameter values representative of the impedance matching network or the photoconductive switches that can be adjusted. The method further includes selecting one or more optimization goals for the impedance matching network and the one or more photoconductive switches, and adjusting the one or more parameter values according to the one or more optimization goals. The one or more optimization goals include an efficiency at a particular power output.

High efficiency photoconductive semiconductor switch-based amplifier for high power microwave transmission

In one embodiment, an apparatus includes at least one vertical transistor, where the at least one vertical transistor includes: a substrate comprising a semiconductor material, an array of three dimensional (3D) structures above the substrate, a gate region, and an isolation region positioned between the 3D structures. Each 3D structure includes the semiconductor material. Each 3D structure also includes a first region having a first conductivity type and a second region having a second conductivity type, the second region including a portion of at least one vertical sidewall of the 3D structure. The gate region is present on a portion of an upper surface of the second region and the gate region is coupled to a portion of the at least one vertical sidewall of each 3D structure.

Methods and devices for illuminating a photoconductive switch consisting of an optically actuated photoconductive material situated between two electrodes are described. Light from a light source is coupled to an optical fiber, which is attached to a frustum, the other side of which is proximate to the photoconductive switch. Light from the optical fiber enters the frustum, spreads out, and enters the photoconductive switch via the top-side electrode. Some of the light is absorbed, while the remaining light reflects off the bottom-side electrode, travels back through the photoconductive switch, and any unabsorbed light reenters the frustum. The geometry of the frustum is configured such that most of the light reflects back into the switch itself with only a negligible fraction escaping from the optical fiber, which advantageously results in near total utilization of the light.

Illumination frustums for photoconductive switches

Wide bandgap optical switch circuit breaker

Devices, methods and techniques are disclosed for providing a multi-layer diode without voids between layers. In one example aspect, a multi-stack diode includes at least two Drift Step Recovery Diodes (DSRDs). Each DSRD comprises a first layer having a first type of dopant, a second layer forming a region with at least ten times lower concentration of dopants compared to the adjacent layers, and a third layer having a second type of dopant that is opposite to the first type of dopant. The first layer of a second DSRD is positioned on top of the third layer of first DSRD. The first layer of the second DSRD and the third layer of the first DSRD are degenerate to form a tunneling diode at an interface of the first DSRD and second DSRD, the tunneling diode demonstrating a linear current-voltage characteristic.

Tunnel drift step recovery diode

In one embodiment, a method of forming a vertical transistor includes forming a layer comprising a semiconductor material above a substrate, defining three dimensional (3D) structures in the layer, forming a second region in at least one vertical sidewall of each 3D structure, and forming an isolation region between the 3D structures. In another embodiment, an apparatus includes at least one vertical transistor, where the at least one vertical transistor includes: a substrate comprising a semiconductor material, an array of 3D structures above the substrate, and an isolation region positioned between the 3D structures. Each 3D structure includes the semiconductor material. Each 3D structure also includes a first region having a first conductivity type and a second region having a second conductivity type, the second region including a portion of at least one vertical sidewall of the 3D structure.

According to one embodiment, an apparatus includes at least one vertical transistor, where the at least one vertical transistor includes: a substrate including a semiconductor material; an array of three dimensional (3D) structures above the substrate; and an isolation region positioned between the 3D structures. Each 3D structure includes the semiconductor material. Each 3D structure also includes a first region having a first conductivity type and a second region having a second conductivity type, where the second region includes a portion of at least one vertical sidewall of the 3D structure.

According to one embodiment, an apparatus includes a substrate, and at least one three dimensional (3D) structure above the substrate. The substrate and the 3D structure each include a semiconductor material. The 3D structure also includes: a first region having a first conductivity type, and a second region coupled to a portion of at least one vertical sidewall of the 3D structure.

Three dimensional vertically structured MISFET/MESFET

Techniques, systems, and devices are disclosed that relate to coaxial photoconductive switch modules. The coaxial photoconductive switch may include an outer conductor, an inner conductor, and a photoconductive material positioned between the inner conductor and the outer conductor. The inner conductor, the outer conductor, and the photoconductive material have a predetermined height. A bias voltage may be applied between the inner conductor and the outer conductor. When light of a predetermined wavelength and a predetermined intensity is incident on the photoconductive material, the photoconductive material may break down allowing a current to flow through the photoconductive material between the inner conductor and the outer conductor.

Three-dimensional co-axial linear photonic switch

Growing community of inventors

Livermore, CA, United States of America

Adam M Conway