Electronic structure of a narrow-gap semiconductor KAg_(3)Te_(2)  

作　　者：Rong Feng Haotian Zheng Haoran Liu Binru Zhao Xunqing Yin Zhihua Liu Feng Liu Guohua Wang Xiaofeng Xu Wentao Zhang Weidong Luo Wei Zhou Dong Qian 冯荣;郑昊天;刘浩然;赵彬茹;尹训庆;刘智华;刘峰;王国华;许晓峰;张文涛;罗卫东;周苇;钱冬

机构地区：[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

出　　处：《Chinese Physics B》2025年第4期523-526,共4页中国物理B(英文版)

基　　金：Project supported by the National Key Research and Development Program of China and the National Natural Science Foundation of 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~0.4 eV and p-type character.The infrared transmission spectra of single crystals yielded an optical band gap of~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(~0.12 me).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.

关 键 词：KAg_(3)Te_(2)crystals narrow-gap semiconductor angle-resolved photoemission spectroscopy small effective hole mass dimensional anisotropy 

分 类 号：O469[理学—凝聚态物理]