Ultra-wide bandgap Semiconductors Group
2023.04.01 Update
Toward the realization of carbon-neutral society, reduction of electrical energy consumption is an urgent task. Virtually all the electrical equipment has a power converter to supply electricity with appropriate voltage and current. Power semiconductor devices (power devices) are key components of a power converter to efficiently handle the electricity. Therefore, improvement in the efficiency of such devices is essential for efficient energy use. At present, most of power devices are produced using Si. However, performance of Si-based power devices is now close to the material limit. Use of wide-bandgap semiconductors is promising to further improve the device performance beyond Si. Indeed, SiC- or GaN-based power devices have started penetrating the market. On the other hand, our research targets are ultra-wide-bandgap (UWBG) semiconductors such as diamond and Ga2O3, which have greater potential even beyond SiC and GaN for power device applications. We will contribute to the realization of high-performance UWBG power devices through deep investigations on thin film growth and characterizations combining device physics based on UWBG materials science.
Specialized Research Field
To put UWBG semiconductors in practical use, many technical issues need to be addressed. Reduction in crystal defect density, metastability management, doping control, contact formation, and electric field management are examples of such technical issues. We are developing novel epitaxial growth and interface control technologies regarding UWBG semiconductors. The main research targets are diamond and Ga2O3 at present, and we will also try further novel materials.