Kai Zhu1, Tsutomu Miyasaka2, Jin Young Kim3, Iván Mora-Seró4. 1. †National Renewable Energy Laboratory, Golden, Colorado 80401, United States. 2. ‡Toin University of Yokohama, Yokohama, Kanagawa 225-8503, Japan. 3. §Korea Institute of Science and Technology, Seongbuk-gu, Seoul 136-791, Republic of Korea. 4. ⊥Institute of Advanced Materials (INAM), Universitat Jaume I, Castelló de la Plana 12071, Spain.