1. Department
of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
2. Research Center
for Photovoltaics (RCPV), National Institute of Advanced Industrial
Science and Technology (AIST), 1-1-1
Higashi, Tsukuba, Ibaraki 305-8565, Japan