1. Department of Electrical and Computer Engineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
2. Department of Materials Science and Engineering, Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, United States
3. Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, Wright-Patterson AFB, Ohio 45433, United States
4. Department of Materials Science and Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
5. Department of Electrical and Computer Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States