1. Department of Physics and Semiconductor Science Dongguk University Jung‐gu Seoul 04620 South Korea
2. Quantum‐functional Semiconductor Research Center Dongguk University Seoul 04620 Republic of Korea
3. Department of Chemical Engineering Inha University Incheon 22212 Republic of Korea
4. Program in Biomedical Science and Engineering Inha University Incheon 22212 Republic of Korea
5. Department of Radiation Oncology Asan Medical Center Seoul 05505 Republic of Korea