1. Center for Electronic Materials, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
2. Center for Energy Harvesting Materials and System (CEHMS), Bio-Inspired Materials and Devices Laboratory (BMDL), Virginia Tech., Blacksburg, Virginia 24061, United States
3. Aviation and Missile Research Development, and Engineering Center, U.S. Army RDECOM, Redstone Arsenal, Huntsville, Alabama 35898, United States
4. Department of Geosciences, Virginia Tech., Blacksburg, Virginia 24061, United States
5. Department of Materials Science and Engineering, Virginia Tech., Blacksburg, Virginia 24061, United States