July 27: A research team led by Dr. Seo, Jae hwa at Korea Electrotechnology Research Institute Advanced Semiconductor Research Center, working with Professor Yoon, Young jun’s team at Gyeongkuk National University, has achieved Korea’s first demonstration of a silicon carbide -based betavoltaic cell designed to generate electricity for more than 50 years without recharging or replacement even in extreme environments such as space and the polar regions. The findings have drawn international attention, having been published in the International Journal of Energy Research, a leading global journal in the energy field ranked in the top 3.6% by JCR and second in its subject category.
A betavoltaic cell is a next-generation power device in which a semiconductor absorbs electrons naturally emitted by radioactive material and converts them into electricity. Much like a solar cell converts light into electricity, a betavoltaic cell works on the same principle but draws its energy from radioactive material instead of sunlight. That means it can deliver stable power over long periods, regardless of weather or temperature, even where sunlight never reaches, such as space, the deep sea, underground, or defense-surveillance sites. However, progress in Korea has been hampered by low energy collection efficiency and the absence of infrastructure to safely handle radioactive materials or evaluate device performance, making it difficult to demonstrate the technology domestically.
To overcome these limitations, KERI utilized SiC, a next-generation material that is far more resistant to heat and radiation than conventional silicon. By optimizing a p-i-n diode structure to maximize the conversion of radiation into electricity, the team successfully developed its own proprietary betavoltaic semiconductor device.
With the core technology in hand, the team tackled its greatest challenge, which was demonstrating the device using actual radioactive material. After clearing rigorous safety protocols, the researchers obtained nickel-63(Ni-63), a beta-emitting isotope, and established Korea’s first specialized measurement system. By combining the semiconductor with the radioactive source, the team confirmed actual power generation of 160 µW/cm² (160 microwatts per square centimeter) of active area. A microwatt is defined as one-millionth of a watt and successfully built a prototype capable of powering a low-power LED. Given the decay characteristics of Ni-63, this indicates that KERI’s device can operate for more than 50 years without a battery replacement in ultra-low-power environments, such as those typically requiring coin-type lithium batteries. This output represents a 60,000-fold improvement over previously reported experimental results in Korea, representing one of the highest reported power-density levels in Korea.
Electron-beam tests designed to emulate an ideal direct-deposition configuration, in which Ni-63 forms a thin and uniform layer on the semiconductor surface, indicated a potential output power density of 0.85 mW/cm² and more than 20 µW per unit cell. This figure is more than 4,200 times higher than Korea’s previous unit-cell performance target. The long half-life of Ni-63 gives the technology the potential for century-scale power generation. By expanding the cell size and stacking multiple units for integration, KERI has secured the core technology necessary to compete with commercial products from leading global competitors.
Following the successful prototype demonstration, the team leveraged AI modeling and extreme-environment testing to enhance both the technological maturity and the commercial viability. In collaboration with Professor Yoon, Young jun’s team at Gyeongkuk National University, the researchers developed an AI predictive model that forecasts the cell’s output power and voltage with 98 to 99 percent accuracy, significantly reducing design optimization time. The team also conducted Korea’s first experiment directly irradiating the cell with high-energy 15 MeV (megaelectronvolt) protons to simulate the intense radiation environment a spacecraft might encounter. This level of exposure to protons accelerated by 15 million volts simulates one component of the space radiation environment, where a spacecraft is constantly bombarded by unshielded radiation. By measuring the cell’s endurance under these harsh conditions, the team obtained quantitative reliability-degradation data. The tests provided quantitative reliability-degradation data needed to assess and improve the device’s suitability for future space missions.
Dr. Seo, Jae hwa of KERI said,
“A betavoltaic cell is not designed for high-power applications like those in electric vehicles. Instead, it serves as an ultra-long-life power source that steadily delivers small amounts of electricity for decades without maintenance, making it well suited for remote environments that are difficult for humans to access.” He stressed that the technology is expected to serve as “a power source for unmanned defense surveillance sensors that consume extremely little power in standby mode while storing power to periodically transmit signals, as well as for emergency beacons in space and the deep sea, enabling autonomous operation for more than 50 years.” Professor Yoon, Young jun of Gyeongkuk National University added, “This milestone goes far beyond simple computer simulations or basic research. By encompassing the entire process of fabrication, measurement, and prototype demonstration, enhanced by AI-driven design predictions, this achievement stands as one of the most advanced of its kind in Korea.”
Backed by the manufacturing processes and measurement infrastructure developed through this project, KERI has filed related patent applications. Moving forward, KERI plans to collaborate with private companies across the aerospace, defense, nuclear power, radiation safety, and remote sensing sectors to drive technology transfers and joint product development.
KERI is a government-funded research institute affiliated with the National Research Council of Science and Technology under the Ministry of Science and ICT. This research was conducted with support from KERI Research Program, “Development of Next-Generation SiC-Based Betavoltaic Cells for Space Exploration.”
