Direct Visualization and Manipulation of Tunable Quantum Well State in Semiconducting Nb2SiTe4

Jing Zhang; Zhilong Yang; Shuai Liu; Wei Xia; Tongshuai Zhu; Cheng Chen; Chengwei Wang; Meixiao Wang; Sung-Kwan Mo; Lexian Yang; Xufeng Kou; Yanfeng Guo; Haijun Zhang; Zhongkai Liu; Yulin Chen

doi:10.1021/acsnano.1c03666

Direct Visualization and Manipulation of Tunable Quantum Well State in Semiconducting Nb₂SiTe₄

ACS Nano. 2021 Oct 26;15(10):15850-15857. doi: 10.1021/acsnano.1c03666. Epub 2021 Oct 13.

Authors

Jing Zhang^{1

2}, Zhilong Yang³, Shuai Liu^{1

2

4}, Wei Xia^{1

5}, Tongshuai Zhu³, Cheng Chen^{1

6}, Chengwei Wang^{1

2

7}, Meixiao Wang^{1

5}, Sung-Kwan Mo⁶, Lexian Yang⁸, Xufeng Kou^{5

9}, Yanfeng Guo¹, Haijun Zhang³, Zhongkai Liu^{1

5}, Yulin Chen^{1

5

8

10}

Affiliations

¹ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ National Laboratory of Solid-State Microstructures, School of Physics and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
⁴ Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
⁵ ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China.
⁶ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
⁷ Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
⁸ State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
⁹ School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China.
¹⁰ Department of Physics, University of Oxford, Oxford, OX1 3PU, U.K.

PMID: 34644492
DOI: 10.1021/acsnano.1c03666

Abstract

Quantum well states (QWSs) can form at the surface or interfaces of materials with confinement potential. They have broad applications in electronic and optical devices such as high mobility electron transistor, photodetector, and quantum well laser. The properties of the QWSs are usually the key factors for the performance of the devices. However, direct visualization and manipulation of such states are, in general, challenging. In this work, by using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we directly probe the QWSs generated on the vacuum interface of a narrow band gap semiconductor Nb₂SiTe₄. Interestingly, the position and splitting of QWSs could be easily manipulated via potassium (K) dosage onto the sample surface. Our results suggest Nb₂SiTe₄ to be an intriguing semiconductor system to study and engineer the QWSs, which has great potential in device applications.

Keywords: angle-resolved photoemission spectroscopy; band structure engineering; narrow gap semiconductor; quantum well states; two-dimensional material.