1. Physics Characterization and Simulations Lab (PCSL), Department of Physics, School of Natural Sciences (SNS), National University of Sciences and Technology (NUST), Islamabad 54000, Pakistan
2. Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758, United States;
3. Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States;