1. Center of Excellence for Green Nanotechnologies, Microelectronics and Semiconductor Institute, King Abdulaziz City for Science and Technology, Riyadh 11442, Saudi Arabia
2. Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
3. Material, Physical, and Chemical Sciences Center, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
4. Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States