1. Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, United States
2. Department of Chemistry, Stanford University, Stanford, California 94305-5025, United States
3. Department of Materials Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan
4. School of Polymer Science and Engineering, Center for Optoelectronic Materials and Device, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
5. Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
6. Department of Organic Materials Science, Yamagata University, Yamagata 992-8510, Japan