Skip to main content
Image
Custom PCB design of a PCSS Laser Diode Driver

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.

Image
JFET Device Structure

LLNL’s novel approach is to use diamond substrates with the desired donor (nitrogen) and acceptor (boron) impurities.   In order to optically activate these deep impurities, the invention requires at least one externally or internally integrated light source.  The initial exposure to light can set up the desired conduction current, after which the light source could be turned off.  Even with…

Image
Tunneling Diode between two DSRDs

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. 

Image
thermoelectric cooler (TEC) embedded substrate for cooling of high power devices

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…

Image
SEM image of a prototype for a neural implant shuttle etched into a non-SOI wafer. The 7:1 (Si:Photoresist) etch selectivity used here allowed for a maximum structure height of 32 μm, with up to 75 steps of 0.4 μm height each. Scale bar 100 μm.

For this method, a Silicon on Insulator (SOI) wafer is used to tailor etch rates and thickness in initial steps of the process.  The simple three step process approach is comprised of grayscale lithography, deep reactive-ion etch (DRIE) and liftoff of the SOI wafer.  The liftoff process is used to dissolve the insulating layer, thus separating sections of the wafer as individual silicon…

Image
Unique LLNL capabilities enable GaN superjunctions

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…

Image
Schematic of high density detachable electrical interfaces with a single layer

Many of the disadvantages of current interface devices can be overcome with LLNL’s novel interface design, which relies on area array distribution where independent interface connector subassemblies are positioned in a planar grid.  Not only is the interface device expandable area-wise (without increasing contact force), but it could also be expanded height-wise, with multiple layers of these…

Image
Flexible optoelectronic chip with integrated transmitter and receiver subassemblies

Commercial fiber optic cables are the current standard for carrying optical signals in industries like communications or medical devices. However, the fibers are made of glass, which do not have favorable characteristics for applications that require flexibility and re-routing, e.g. typically brittle, limited selection of materials, dimension constraints.

Image
iChip, brain on a chip

LLNL has developed a brain-on-a-chip system with a removable cell-seeding funnel to simultaneously localize neurons from various brain regions in an anatomically relevant manner and over specific electrode regions of a MEA. LLNL’s novel, removable cell seeding funnel uses a combination of 3D printing and microfabrication that allows neurons from select brain regions to easily be seeded into…