1. Department of Electrical and Computer Engineering Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of Korea
2. Department of Energy Science and Center for Artificial Atoms Sungkyunkwan University Suwon 16419 Republic of Korea
3. Department of Electronics Engineering Sookmyung Women's University Seoul 04310 Republic of Korea
4. SKKU Advanced Institute of Nanotechnology (SAINT) Sungkyunkwan University Suwon 16419 Republic of Korea