1. Address State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, and School of Physics and Engineering; Sun Yat-sen University; Guangzhou 510275 PR China
2. Inorganic Nanostructured Materials Group; MANA, National Institute for Materials Science; Namiki 1-1 Tsukuba, Ibaraki 305-0044 Japan
3. International Center for Young Scientists (ICYS); National Institute for Materials Science; Namiki 1-1 Tsukuba, Ibaraki 305-0044 Japan
4. Nanotube Group; MANA, National Institute for Materials Sciences; Namiki 1-1 Tsukuba, Ibaraki 305-0044 Japan