1. Center
for Organic Photonics and Electronics Research (OPERA) and
JST, ERATO, Adachi Molecular Exciton Engineering Project, ‡Department of Automotive
Science, Graduate School of Integrated Frontier Sciences, and §International Institute
for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744
Motooka, Nishi, Fukuoka 819-0395, Japan