1. Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
3. Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy
4. Physical and Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
5. Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States
6. KBR Inc., Beavercreek, Ohio 45431, United States
7. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States