1. Research Center for Condensed Matter Physics, Hiroshima Institute of Technology, Hiroshima 731-5193, Japan
2. Department of Chemistry, College for Humanities and Sciences, Nihon University, Setagaya, Tokyo 156-8550, Japan
3. Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa 239-8686, Japan
4. Condensed Molecular Materials Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
5. Flexible Electronic Research Center, AIST, Tsukuba, Ibaraki 305-8562, Japan