Opportunity:

Lawrence Livermore National Laboratory (LLNL), operated by the Lawrence Livermore National Security (LLNS), LLC under contract no. DE-AC52-07NA27344 (Contract 44) with the U.S. Department of Energy (DOE), is offering the opportunity to enter into a collaboration to further develop its optimization methods to building diamond PCSS.

Background:

High frequency switching is required for many applications including inverters, pulsed power, and generation of electromagnetic waves.  Previous photoconductive switches have been based on semiconductors such as Si, GaAs, GaN, or SiC.  Diamond is superior to these materials in terms of critical electric field, carrier mobility, and thermal conductivity, making it the best candidate for photoconductive semiconductor material.   What follows is a method to build efficient, high power diamond PCSS including selection of wavelength and selection of anode and cathode materials.

Description:

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:

1. Diamond material doped with substitutional nitrogen to act as a source of electrons. 
   • Diamond plate can be made very thin to produce thin diamond PCSS
2. The device architecture allows maximum light entering the aperture.  Double-sided illumination is used to optimize the absorption of UV light in thicker devices.  3D optical structures patterned on the device surface allows for increased power efficiency.
3. The top and bottom electrodes are made of ultra-wide bandgap (UWBG) transparent conductors or materials with high reflectivity with a metal ring for soldering connection. 
4. Transparent conductive layer on diamond to produce a surface that is.
   • altered to create an electrically conductive yet optically transparent patterned region
   • anti-reflective
5. Increased performance at shorter wavelengths due to photon recycling effect
6. Designed to increase voltage hold off

Advantages/Benefits:

The diamond photoconductive switch has higher efficiency (~20%) and output power (~50 kW) compared to conventional switches.  LLNL’s diamond-based photoconductive switch technology has optimized performance with numerous advantages over traditional optical switches, such as:

• Maintains high critical electric field
• Higher breakdown voltage
• Diamond has the best combination of material properties for switches

Potential Applications:

• High Power Microwave Sources
• High frequency switching
• Pulsed Power physics

Development Status: 

Current stage of technology development:  TRL 3

LLNL has filed for patent protection on this invention.

LLNL is seeking industry partners with a demonstrated ability to bring such inventions to the market. Moving critical technology beyond the Laboratory to the commercial world helps our licensees gain a competitive edge in the marketplace. All licensing activities are conducted under policies relating to the strict nondisclosure of company proprietary information. 

Please visit the IPO website at https://ipo.llnl.gov/resources for more information on working with LLNL and the industrial partnering and technology transfer process.

Note:  THIS IS NOT A PROCUREMENT.  Companies interested in commercializing LLNL's SOS with eliminated pre-pulses should provide an electronic OR written statement of interest, which includes the following:

1. Company Name and address.
2. The name, address, and telephone number of a point of contact.
3. A description of corporate expertise and/or facilities relevant to commercializing this technology.

Please provide a complete electronic OR written statement to ensure consideration of your interest in LLNL's SOS with eliminated pre-pulses.

The subject heading in an email response should include the Notice ID and/or the title of LLNL’s Technology/Business Opportunity and directed to the Primary and Secondary Point of Contacts listed below.

Written responses should be directed to:

Lawrence Livermore National Laboratory

Innovation and Partnerships Office

P.O. Box 808, L-779

Livermore, CA  94551-0808

Attention:   IL-13770andIL-13810