A thyristor will stay conducting until the current through the device is zero (“current zero”) or perhaps slightly negative. LLNL’s approach is to use the opticondistor (“OTV”) to force this current zero in order to force the device into an “off” state. By combining a light-activated thyristor with an OTV, a noise-immune, high efficiency, high-power switching device can be constructed. The…
Keywords
- Show all (208)
- Instrumentation (39)
- Additive Manufacturing (37)
- Sensors (16)
- Synthesis and Processing (16)
- Diagnostics (13)
- Electric Grid (8)
- Imaging Systems (8)
- 3D Printing (7)
- Materials for Energy Products (7)
- Carbon Utilization (6)
- Semiconductors (6)
- Compact Space Telescopes (5)
- Data Science (5)
- Laser Materials Processing (5)
- Cybersecurity (4)
- Diode Lasers (4)
- Material Design (4)
- (-) Photoconductive Semiconductor Switches (PCSS) (9)
- (-) Therapeutics (5)
- (-) Optical Switches (4)
![A cross-sectional schematic of a diffused Ga2O3 photoconductive semiconductor switch (PCSS)](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/a%20cross-sectional%20schematic%20of%20a%20diffused%20beta-Ga2O3%20PCSS.png?itok=Z41s0FbO)
The researchers’ approach leverages the concept that dopants have high diffusivities in Ga2O3; the key lies in the selection of the appropriate dopant. This LLNL invention describes two device types that employ this design:
![Samples of optimized diamond switches](/sites/default/files/styles/scale_exact_400x400_/public/2024-01/Samples%20of%20optimized%20diamond%20switches.png?itok=5syzdD0q)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength.
Characteristics of the LLNL-developed switch are as follows:
![OALV design with High-k Photoconductor and High-k Optical Window](/sites/default/files/styles/scale_exact_400x400_/public/2024-01/OALV%20design.png?itok=xMV74hXb)
LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments. These designs include:
![Custom PCB design of a PCSS Laser Diode Driver](/sites/default/files/styles/scale_exact_400x400_/public/2023-11/PCSS%20Laser%20Diode%20Driver.png?itok=WQ2FNHQF)
LLNL researchers have invented an ultrafast PCSS to drive a high-power laser diode with arbitrary pulse widths. These devices operate by supplying a high voltage (>10 kV) to one side of the switch. A short pulse of light illuminates the semiconductor, instantly turning it from highly resistive to highly conductive.
![twister oven component with reflective inner cylinder surface](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/twister%20oven%20component.png?itok=v3jlzm2V)
U.S. Patent No. 11,555,965 describes LLNL’s invention of “Illumination Frustums” for photoconductive switches to capture and “frustrate” the light from leaving the frustum. LLNL researcher’s latest novel invention, “Twister Oven”, achieves this by encouraging laser light absorption in a photo conductor material. Light enters the oven twisting and reflecting, making near normal incident multi…
![A photoconductive switch made from a synthetic, chemical vapor deposition diamond under test](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/Photoconductive%20switch.jpg?itok=xC1O7vXg)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is chosen to be doped with substitutional nitrogen to act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra-wide bandgap (UWBG)…
![schematic of LLNL’s field emission photocathode device architecture with examples of tunable SiC surface micro- and nanostructures fabricated at LLNL](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/FE%20photocathode%20device.png?itok=z-1Om9v8)
LLNL researchers faced this challenge by bridging the gap between VEDs and solid-state electronics (SSE). Their approach was to create a hybrid vacuum microelectronic device (VMD) architecture that combines the properties of vacuum as the electronic medium and the compact form factor and manufacturing scalability of semiconductor microelectronic chips.
![Segments of transmission line lengths can be switched to open circuit (as shown) or shorted to the ground (not shown)](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/Segments%20of%20tranmission%20line%20lengths.png?itok=FF0qaBGw)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is specifically doped with substitutional nitrogen, which act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra wide band gap (UWBG)…
![Annular illumination on photo conductor by Conical Total Internal Reflection “CTIR” endcap](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/CONIFR.png?itok=L4wSanXF)
The approach is to use a custom-designed frustrum and attach it to the optical fiber that connects to the PCSS. Light from the fiber enters the frustrum, spreads out, and enters the PCSS. Any unabsorbed light re-enters the frustrum and, because of its geometry, reflects back into the PCSS itself with only a negligible fraction escaping from the fiber. The shape of the novel frustrum is…
![The image is a montage of an artist’s depiction of a liposomal drug carrier studded with carbon nanotube porins that is docking to a cancer cell surface and delivering chemotherapy cargo with a fluorescence microscopy image of stained cells exposed to these carriers. The red stain indicates that the cells are dead and the treatment was successful. Images by P. Lastrico of MPI and N.T. Ho and A. Noy of LLNL.](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/liposomal%20drug%20carrier%20with%20CNT%20porins.jpg?itok=HvCCyUTI)
To address shortcomings of current liposome drug delivery systems, the patented innovation uses drug-loaded liposomes containing carbon nanotube porins (CNTPs) inserted into the liposomal membranes for the delivery of the encapsulated drugs. Short CNTPs (10 nm in length) with narrow diameter (0.8 nm) has been demonstrated to facilitate efficient fusion of lipid bilayers resulting in the…
![SEM image of iron-sulfide spheres](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/iron-sulfide%20spheres.jpg?itok=X03OXhag)
A new approach of developing synthetic antibacterial mineral assemblages can be used as an alternative treatment when traditional antibiotics fail in clinical and agricultural settings. Mineral mixtures can be synthesized with tunable metal release and reactive oxygen species generation that are capable of killing human pathogens and promoting wound healing. One of the key components in the…
![novel thiacrown ethers for isolating of 197gHg and 197m,gHg](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/novel%20thiacrown%20ether.png?itok=afjvUtSX)
The method described in a pending patent application uses a novel thiacrown (dibenzohexathia-18-crown-6) for efficient extraction of 197m,gHg and 197gHg from irradiated Pt target foils. The separation of 197m,gHg and 197gHg from Pt foils using this novel thiacrown was found to be highly specific. No detectable amount of the Pt foil was seen in the…
![High Density Protein Translation System: Nanotubes used to greatly increase the density of ribosomes on a surface by adding a third dimension (height) to enable multiple ribosomal attachment sites.](/sites/default/files/styles/scale_exact_400x400_/public/2023-04/High%20Density%20Protein%20Translation%20System.png?itok=zerUPjta)
Combining the principles of nanotechnology, cell-free protein synthesis and microfluidics, LLNL researchers have developed a reusable, portable programmable system that can create purified, concentrated protein product in vitro in a microfluidic device containing nucleic acids.
![blue bacteria](/sites/default/files/styles/scale_exact_400x400_/public/2022-07/blue%20bacteria.jpg?itok=ddcclBXg)
LLNL scientists developed novel hydrogels, which are biodegradable soft materials synthesized by a water-soluble polymer. Incorporating silver imparts antimicrobial activity to the material at low concentration compared to currently used silver nanoparticles. Our hydrogels are composed of silver ions instead of silver nanoparticles, which eliminates the toxicity concerns of modern silver…
![OTV Image](/sites/default/files/styles/scale_exact_400x400_/public/2022-02/OTV%20Image.png?itok=KEAmHqpM)
The Optical Transconductance Varistor (OTV, formerly Opticondistor) overcomes depletion region voltage limitations by optically exciting wide bandgap materials in a compact package. A 100μm thick crystal could have the capability approaching 40kV and would replace numerous equivalent junction devices. Thus, unlike present junction transistors or diodes, this wide bandgap device can be stacked…