1. Department of Physics Wake Forest University Winston Salem NC 27109 USA
2. Flexible Electronics Research Center National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Ibaraki 305‐8565 Japan
3. Engineering Physics Division National Institute of Standards and Technology (NIST) Gaithersburg MD 20899‐1070 USA
4. Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 38831 USA
5. School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics Georgia Institute of Technology Atlanta GA 30332 USA
6. Department of Applied Physics The University of Tokyo 7‐3‐1 Hongo Bunkyo‐ku Tokyo 113‐8656 Japan