中国物理B ›› 2025, Vol. 34 ›› Issue (4): 47102-047102.doi: 10.1088/1674-1056/adb680
Electronic structure of a narrow-gap semiconductor KAg3Te2
Rong Feng(冯荣)1, Haotian Zheng(郑昊天)1, Haoran Liu(刘浩然)1, Binru Zhao(赵彬茹)1, Xunqing Yin(尹训庆)1, Zhihua Liu(刘智华)1, Feng Liu(刘峰)1, Guohua Wang(王国华)1, Xiaofeng Xu(许晓峰)2, Wentao Zhang(张文涛)1,3, Weidong Luo(罗卫东)1, Wei Zhou(周苇)4, and Dong Qian(钱冬)1,5,6,†
- 1 Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China;
2 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China;
3 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
4 School of Electronic and Information Engineering, Changshu Institute of Technology, Changshu 215500, China;
5 Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China;
6 Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
Electronic structure of a narrow-gap semiconductor KAg3Te2
Rong Feng(冯荣)1, Haotian Zheng(郑昊天)1, Haoran Liu(刘浩然)1, Binru Zhao(赵彬茹)1, Xunqing Yin(尹训庆)1, Zhihua Liu(刘智华)1, Feng Liu(刘峰)1, Guohua Wang(王国华)1, Xiaofeng Xu(许晓峰)2, Wentao Zhang(张文涛)1,3, Weidong Luo(罗卫东)1, Wei Zhou(周苇)4, and Dong Qian(钱冬)1,5,6,†
- 1 Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China;
2 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China;
3 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
4 School of Electronic and Information Engineering, Changshu Institute of Technology, Changshu 215500, China;
5 Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China;
6 Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
摘要： KAg$_{3}$Te$_{2}$ with a layered crystal structure has been predicted to be a possible topological insulator. Through electrical transport measurements, we revealed its semiconducting behavior with a narrow band gap of $\sim 0.4$ eV and p-type character. The infrared transmission spectra of single crystals yielded an optical band gap of $\sim 0.3$ eV. Angle-resolved photoemission spectroscopy reveals a bulk energy gap at the Brillouin zone center, with no observable surface state, suggesting that KAg$_{3}$Te$_{2}$ is a topological trivial narrow-gap semiconductor. The experimentally determined effective mass of the holes in KAg$_{3}$Te$_{2 }$ is very small ($\sim 0.12 m_{\rm e}$). The valence band maximum is quasi-two-dimensional, while the conduction band minimum is fully three-dimensional. Such intriguing dimensional anisotropy can be attributed to the distinct orbital contributions from K, Ag, and Te atoms to the respective bands.
中图分类号: (Semiconductor compounds)
- 71.20.Nr