Author Affiliations

Xiao Sun,^1,* Weiqing Cheng,¹ Song Liang,^2,3 Shengwei Ye,¹ Yongguang Huang,^2,3 Yiming Sun,¹ Ruikang Zhang,^2,3 Jichuan Xiong,³ Xuefeng Liu,³ John H. Marsh,¹ and Lianping Hou¹

¹James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, U.K.

²College of Physics, Jilin University, Changchun 130012, China

³Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, China

⁴School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

^*Corresponding author: x.sun.2@research.gla.ac.uk