1. State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, No.3888 Dongnanhu Road, Changchun, 130033, People's Republic of China
2. University of Chinese academy of sciences, Beijing 100039, People's Republic of China
3. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
4. Department of Mechanical Engineering, University of California at Berkeley, Berkeley, California 94720, USA