Takeshi Ohshima is the Director of Quantum Materials and Applications Research Center (QUARC) at National Institutes for Quantum Science and Technology (QST), Japan. He also works at Department of Materials Science, Tohoku University, Japan as Specially Appointed Professor. He studies radiation effects on semiconductor materials and device including solar cells for space and nuclear applications, spin defects in wide bandgap semiconductors for quantum technologies, such as nitrogen-vacancy (NV) center in diamond and silicon vacancy in silicon carbide. He has many collaborators all over the world. As a result, he published more than 500 co-authored peer-reviewed journal articles and 7 book chapters. He organized 20 international conferences as committee members, such as Technical Program Committee of International Conference on Silicon Carbide and Related Materials (ICSCRM), Program committee of IEEE Photovoltaic Specialists Conference (PVSC) and Scientific Committee, of the international conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA). He is Specialty Chief Editor of Quantum Sensing and Metrology, Frontiers in Quantum Science and Technology and Editorial Board of Quantum Beam Science, MDPI.