Theoretical Studies and Basic Research on SiC Photoconductive Solid-State Switches (PCSS) for High Power Microwave Generation
Abstract
ABSTRACT This proposal is focused on the theoretical study and basic research on photoconductive solid-state switches (PCSS) based on the wide bandgap SiC material. This effort would strongly support and couple with an ongoing ONR-funded project at Texas Tech University relating to the Development of SiC Photonic to RF Converters for HPM Generation. The Principle Investigator (PI), Prof. Ravi P. Joshi, has recently transferred to Texas Tech University (TTU), and is an expert in theoretical modeling and basic analyses on semiconductor physics-based processes, high-field transport, and high power electronic device operation. Here, an eighteen-month effort to study and analyze the operation of SiC photoconductive switches at high applied voltages, their opticalto- electrical conversion efficiencies, operating speeds, potential breakdown issues that are related to reliability (including contact stressing or cracking), the trap characteristics that depend on the processing but can lead to filamentation, and the role of contact geometry. This work will be carried out in close collaboration with the research team headed by Profs. James Dickens and Andreas Neuber at the Texas Tech University (TTU). The contribution from this proposed work to this ONR project would be three-fold: (i) Provide expertise in physics-based modeling of SiC photoconductive solid-state switch operation at high voltages, its conversion efficiency, analyze potential geometries for more robust operation, etc. (ii) Provide and facilitate direct comparisons with experimental data generated at TTU for helping provide a basic understanding of the inherent processes, and to evaluate a large parameter space through simulations for system optimization. (iii) Study the effect of changes in contact geometry, substrate material, deep traps and recombination center density and energies for alleviating some of the issues such as: persistent (or long-lived) photoconductivity, potential localized heating or cracking, and double-injection from contacts. For example, in order to prevent current crowding, reduce the contact resistance, and avoid contact degradation, an n-doped GaN sub-contact layer could be inserted between the contact metal and the high resistivity SiC bulk, and such options will need to be studied and evaluated.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512650
Entities
People
- Ravindra Joshi
Organizations
- Office of Naval Research
- Texas Tech University System
- United States Navy