Computing imaging in shortwave infrared bands enabled by MoTe₂/Si 2D-3D heterojunction-based photodiode

Abstract

Breakthroughs brought about by two-dimensional (2D) materials in the field of photodetection have opened up new possibilities in infrared imaging. However, challenges still exist in fabricating high-density detector arrays using such materials, which are essential for traditional imaging systems. In this study, we present a state-of-the-art computing imaging system that utilizes a MoTe₂/Si self-powered photodetector coupled with flexible Hadamard modulation algorithms. This system demonstrates remarkable capability to produce high-quality images in the shortwave infrared (SWIR) band, surpassing the capabilities of devices based on alternative material systems. The exceptional infrared imaging capability primarily stems from the MoTe₂/Si photodetector’s inherent features, including an ultra-wide spectral range (265–1550 nm) and extremely high sensitivity (linear dynamic range (LDR) up to 123 dB, responsivity (R) up to 0.33 A W^–1, external quantum efficiency (EQE) up to 43% and a specific detectivity (D*) exceeding 2.9 × 10¹¹ Jones). Moreover, the imaging system demonstrates the ability to achieve high-quality edge imaging of objects in the SWIR band (1550 nm), even in strong scattering environments and under low sampling rate conditions (sampling rate of 25%). We believe that this work will effectively advance the application scope of 2D materials in the field of computational imaging in SWIR bands.

Keywords

broadband photodetector / computing imaging / infrared photonics / optical communication / two-dimensional materials

Author summay

Dongfeng Shi, Jiawang Chen, and Menglei Zhu contributed equally to this work.