This LLNL invention is a wide bandgap (WBG) or ultra-wide bandgap (UWBG) material comprising a PCSS that is modified, either chemically through alloying and/or mechanically through strain fields, in order to tune the energetic positions of the valence and/or conduction bands and the associated optical transition energies that create and quench the PCSS responsivity.
![Tunneling Diode between two DSRDs](/sites/default/files/styles/scale_exact_400x400_/public/2023-10/TunnelingDiode.png?itok=DfeB26vp)
Instead of producing individual DSRDs and bonding them, Tunnel DSRD's entire stack structure is grown epitaxially on a n- or p-type silicon wafer, resulting in a novel, “monolithic” stacked DSRD. A tunnel diode is essentially a diode with very highly doped p and n regions such that the reverse breakdown voltage is 200 meV or lower.
![thermoelectric cooler (TEC) embedded substrate for cooling of high power devices](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/TEC%20embedded%20substrate.png?itok=vEz7ndQ8)
For cooling a high power device, the novel approach is to use a thermoelectric cooler (TEC)-based embedded substrate with proper selection of the TEC material as an active cooler. The packaging configuration of TEC allows cooling the entire die without the use of a fluid. The process is compatible with the thin film TEC material. Standard semiconductor processes can be used to manufacture…
![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.
![Unique LLNL capabilities enable GaN superjunctions](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/GaNSuperjunctions.png?itok=UtrYddDz)
The approach is to use Charge Balance Layers (CBLs) to create a superjunction device in wide bandgap materials. These CBLs enable the device to effectively spread the electric field over 2- or 3-dimensions within a semiconductor voltage sustaining layer instead of 1-dimension, thereby increasing the maximum voltage a device is capable of withstanding. The challenge of using CBLs is the…
![AgAg2S reference electrode](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/AgAg2S%20reference%20electrode.jpg?itok=kL2OzfHy)
LLNL has developed a reference electrode that is a great improvement on the widely used silver or platinum wire QRE commonly used in electrochemistry in ionic liquids. This new reference electrode, based on a silver-sulfide coated silver wire, exhibits greatly improved stability over a QRE. The stability of our RE approaches that of the Ag/Ag+ RE, but unlike the Ag/Ag+ RE, the RE reported here…
![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…