Large-Scale Mixed-Dimensional Photodiodes Based on 2D p‑MoTe2 and 3D n‑Si Vertical Heterojunctions

• Published in: ACS applied optical materials Vol. 2; no. 5; pp. 871 - 876
• Main Authors: Wang, Qi, Huang, Xinyue, Liu, Ziqi, Song, Yiwen, Ran, Yuqia, Li, Yanping, Pan, Yu, Ye, Yu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 24.05.2024
• Subjects: two-dimensional semiconductors; mixed-dimensional, Si-based photodiode; large-scale, 2H-MoTe2; vertical heterostructures
• ISSN: 2771-9855; 2771-9855
• DOI: 10.1021/acsaom.4c00121

Silicon-based near-infrared (NIR) photodetectors are essential in various applications, but they face challenges due to limited sensitivity. Photodiodes, which are preferred over photoconductors, are being studied to improve NIR sensitivity through innovative designs and fabrication techniques. Two-dimensional (2D) materials show promise in mixed-dimensional heterostructures with silicon. Here, large-scale arrays of 2H-MoTe2/Si vertical heterostructure photodiodes are presented, with broad optical wave response from visible to the NIR wavelength band. The devices exhibit high responsivity, specific detectivity, external quantum efficiency, and fast response speeds. Furthermore, we demonstrate the NIR imaging capabilities of a 6 × 6 photodiode array made of 2H-MoTe2/Si, highlighting the potential of direct heterogeneous integration of 2D semiconductors with silicon for future silicon-based NIR photodetectors.