Nb2SiTe4: A Stable Narrow-Gap Two-Dimensional Material with Ambipolar Transport and Mid-Infrared Response

Mingxing Zhao; Wei Xia; Yang Wang; Man Luo; Zhen Tian; Yanfeng Guo; Weida Hu; Jiamin Xue

doi:10.1021/acsnano.9b05080

Nb₂SiTe₄: A Stable Narrow-Gap Two-Dimensional Material with Ambipolar Transport and Mid-Infrared Response

ACS Nano. 2019 Sep 24;13(9):10705-10710. doi: 10.1021/acsnano.9b05080. Epub 2019 Sep 5.

Authors

Mingxing Zhao^{1

2

3}, Wei Xia^{1

3}, Yang Wang⁴, Man Luo⁴, Zhen Tian¹, Yanfeng Guo¹, Weida Hu⁴, Jiamin Xue¹

Affiliations

¹ School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China.
² Shanghai Institute of Ceramics, Chinese Academy of Sciences , Shanghai 200050 , China.
³ University of Chinese Academy of Sciences , Beijing 100190 , China.
⁴ State Key Laboratory of Infrared Physics , Shanghai Institute of Technical Physics, Chinese Academy of Sciences , Shanghai 200083 , China.

PMID: 31469545
DOI: 10.1021/acsnano.9b05080

Abstract

Two-dimensional (2D) materials with narrow band gaps (∼0.3 eV) are of great importance for realizing ambipolar transistors and mid-infrared (MIR) detections. However, most of the 2D materials studied to date have band gaps that are too large. A few of the materials with suitable band gaps are not stable under ambient conditions. In this study, the layered Nb₂SiTe₄ is shown to be a stable 2D material with a band gap of 0.39 eV. Field-effect transistors based on few-layer Nb₂SiTe₄ show ambipolar transport with a similar magnitude of electron and hole current and a high charge-carrier mobility of ∼100 cm² V^-1 s^-1 at room temperature. Optoelectronic measurements of the devices show clear response to an MIR wavelength of 3.1 μm with a high responsivity of ∼0.66 AW^-1. These results establish Nb₂SiTe₄ as a good candidate for ambipolar devices and MIR detection.

Keywords: Nb2SiTe4; ambipolar transistor; mid-infrared; narrow gap; stability; two-dimensional material.