1. Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, Guangdong, P. R. China
2. CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, Univ Rennes, Rennes F-35000, France