1. Center for Molecular Systems and Organic Devices (CMSOD), Key Laboratory for Organic Electronics & Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, P. R. China
2. Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics & Information Displays, Institute of Advanced Materials, Nanjing-Tech. University, Nanjing, P. R. China