Researchers in Japan and Germany have developed a groundbreaking process using a 20 kW laser to produce high-purity gallium oxide crystals for use in power electronics in electric cars and photovoltaics. This laser-based process eliminates the need for a crucible, making it a significant advancement in crystal production methods.
The method, known as laser-diode floating zone (LDFZ), offers several advantages over traditional crucible-based methods, such as the Czochralski and edge-defined film-fed growth (EFG) processes. The LDFZ process allows for the production of larger diameter crystals, with the latest results showing crystals with a diameter of up to 30 mm being grown—the largest gallium oxide crystals ever produced using a crucible-free growth process.
The team at the Fraunhofer Institute for Laser Technology ILT in Aachen, Germany, has developed a process-adapted optical system for use with the 20 kW laser, allowing for precise control and targeting of the heat input. This development has enabled the successful growth of high-purity gallium oxide crystals without the limitations of crucible-based methods.
Commissioning of the advanced optical system was done via video conference due to pandemic regulations, demonstrating the cutting-edge research and collaboration between German and Japanese scientists. The National Institute of Advanced Industrial Science and Technology (AIST) in Japan was able to produce gallium oxide crystals with a diameter of up to 12 mm using lower laser powers, and with the new 20 kW system, the research team aims to significantly increase the diameter of the crystals.
While the results of the crystal growth experiments are yet to be published, the successful production of 30 mm diameter gallium oxide crystals using the LDFZ process is a significant step forward for the development of high-purity semiconductor crystals.
This innovative process has the potential to revolutionize the production of wide-bandgap semiconductors like gallium oxide and contribute to advancements in power electronics, electric cars, and photovoltaics.
In conclusion, the collaboration between researchers in Japan and Germany has led to a groundbreaking development in crystal production, marking a new era in the production of high-purity gallium oxide crystals.
