1. State Key Laboratory of Integrated Optoelectronics and College of Electronic Science and EngineeringJilin University Changchun 130012 China
2. Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP)City University of Hong Kong Kowloon Hong Kong S.A.R., China
3. Department of Physics and EngineeringZhengzhou University Zhengzhou 450052 China
4. Department of Chemistry and PhysicsLouisiana State University Shreveport LA 71115 USA