1. Scintillation Materials Research Center; University of Tennessee; Knoxville Tennessee 37996 USA
2. Department of Materials Science and Engineering; University of Tennessee; Knoxville Tennessee 37996 USA
3. Institute for Electronics and Nanotechnology; Georgia Institute of Technology; Atlanta GA 30332 USA
4. Department of Chemical & Biomolecular Engineering; University of Tennessee; Knoxville TN 37996 USA