1. Center for Neuromorphic Engineering, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
2. Electronic Materials Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
3. School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
4. KIST-SKKU Carbon-Neutral Research Center, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
5. KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
6. Division of Nanoscience and Technology, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea