1. Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University 1 , Shanghai 200241, China
2. School of Integrated Circuits & Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology 2 , Wuhan 430074, China
3. School of Physics and Electronic Science, East China Normal University 3 , Shanghai 200241, China