1. a Central Research and Development Laboratory , Showa Shell Sekiyu K. K. , 123-1 Shimokawairi, Atsugi-shi, Kanagawa-Ken , 243-02 , Japan
2. b Department of Display Device Research , Nippondenso Co. Ltd. , Kariya-shi, Aichi-Ken , 448 , Japan
3. c Department of Organic and Polymeric Materials, Faculty of Engineering , Tokyo Institute of Technology , Merguro-Ku, o-Okayama, Tokyo , 152 , Japan