Vertical GaN Photoconductive Semiconductor Switch for HVDC Breakers

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OPEN 2021
Buellton, California
Project Term:
03/31/2022 - 03/30/2025

Critical Need:

Offshore wind and solar power plants require high voltage direct current (HVDC) power lines for efficient power transmission. With the increased number of offshore power plants, a multi-terminal HVDC grid, rather than a point-to-point transmission line, is needed. The lack of a low-cost, fast-acting, high-efficiency HVDC circuit breaker impedes its development. A HVDC circuit breaker is the missing building block in realizing a multi-terminal HVDC grid for highly efficient HVDC transmissions in large-scale off-shore power solar/wind power plants.

Project Innovation + Advantages:

SixPoint Materials and Texas Tech University will develop a photoconductive semiconductor switch (PCSS) that will enable low-cost, fast-acting, high-efficiency, high-voltage HVDC circuit breakers. SixPoint will develop the key material, bulk crystals of semi-insulating gallium nitride (GaN), and Texas Tech will design the device structure and fabricate a 100 kV PCSS. Combining the GaN PCSS with a conventional mechanical switch will create a hybrid HVDC circuit breaker suitable for a multi-terminal HVDC grid. One 100 kV GaN PCSS could potentially replace 56 semiconductor switches made of conventional silicon technology.

Potential Impact:

The advancement of HVDC circuit breaker technology will accelerate the development of multi-point HVDC systems required for offshore wind and solar power plants. If successful, this project will :


Generate electricity to power more than 10 million American homes, increasing energy security.


Cut 78 million metric tons of carbon dioxide emissions.


Support approximately 77,000 jobs in industry and surrounding communities.


ARPA-E Program Director:
Dr. Olga Spahn
Project Contact:
Dr. Tadao Hashimoto
Press and General Inquiries Email:
Project Contact Email:


Texas Tech University

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