supported by the National Natural Science Foundation of China(20971046,21171057,61178037,11004256);Natural Science Foundation of Guangdong Province,China(10351064101000000);Open Fund of the State Key Laboratory of Optoelectronic Materials and Technologies(SunYat-Sen University),China;Appropriative Researching Fund for Professors and Doctors,Guangdong University of Education,China(10ARF14)~~