1. Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of Technology P. R. China
2. Department of ChemistryQueen's University Kingston ON K7L 3N6 Canada
3. School of Materials Science and EngineeringBeijing Institute of Technology 5 South Zhongguancun Street Beijing P. R. China