1. Electronic Materials Research Center, Korea Institute of Science and Technology (KIST), Seoul 02791, Republic of Korea
2. Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
3. KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
4. Division of Materials Science and Engineering, Hanyang University, Seoul 04763, Republic of Korea
5. Center for Neuromorphic Engineering, Korea Institute of Science and Technology (KIST), Seoul 02791, Republic of Korea