Stable mid-infrared polarization imaging based on quasi-2D tellurium at room temperature

Lei Tong,Guoming Yang,Yixiu Wang,Meng Peng,Gary J Cheng,Fang Wang,Maithilee Motlag,Xinyu Huang,Fang Zhong,Licong An,Zheng Li,Qiaodong Sun,Weida Hu,Lei Ye,Peng Wang,Yong Zhang,Wenzhuo Wu

doi:10.1038/s41467-020-16125-8

Abstract

Next-generation polarized mid-infrared imaging systems generally requires miniaturization, integration, flexibility, good workability at room temperature and in severe environments, etc. Emerging two-dimensional materials provide another route to meet these demands, due to the ease of integrating on complex structures, their native in-plane anisotropy crystal structure for high polarization photosensitivity, and strong quantum confinement for excellent photodetecting performances at room temperature. However, polarized infrared imaging under scattering based on 2D materials has yet to be realized. Here we report the systematic investigation of polarized infrared imaging for a designed target obscured by scattering media using an anisotropic tellurium photodetector. Broadband sensitive photoresponse is realized at room temperature, with excellent stability without degradation under ambient atmospheric conditions. Significantly, a large anisotropic ratio of tellurium ensures polarized imaging in a scattering environment, with the degree of linear polarization over 0.8, opening up possibilities for developing next-generation polarized mid-infrared imaging technology.

Highlights

Next-generation polarized mid-infrared imaging systems generally requires miniaturization, integration, flexibility, good workability at room temperature and in severe environments, etc
Detailed Raman spectrum characterizations have been performed to verify the high quality of quasi-2D Te, carrier mobility measured by field-effect transistor (FET)-based devices can reach up to ∼9 × 102 cm[2] V−1 s−1 at room temperature, which is at the forefront in the field of 2D materials
The thickness of Te flake measured by atomic force microscope (AFM) is ∼27.5 nm (Supplementary Fig. 1i–j), and its thicker thickness is beneficial to reach stronger absorption, leading to higher photocurrent, but the thickness should not be too thick, otherwise the overlarge dark current will lead to poor photodetectivity and other performance

Summary

Introduction

Next-generation polarized mid-infrared imaging systems generally requires miniaturization, integration, flexibility, good workability at room temperature and in severe environments, etc. Emerging two-dimensional materials provide another route to meet these demands, due to the ease of integrating on complex structures, their native in-plane anisotropy crystal structure for high polarization photosensitivity, and strong quantum confinement for excellent photodetecting performances at room temperature. Under strongly scattering environment, achieving target photoelectric imaging is hard for 2H-phase MoTe2-based photodetectors which have no polarized photoresponse, the quasi-2D Te-based photodetector reported here can realize imaging for the target with the degree of linear polarization (DoLP) over 0.8 at the wavelength of 2.3 μm. The feasibility of implementing Te for polarized imaging proved in this work is at the first stage, for the step, the integration for authentic facilities in the future requires efforts upon achieving the design and fabrication of quasi-2D Te-based area-array, which worth more investigations

Methods

Results

Conclusion