A High‐Speed Image Sensor Based on Large‐Area MoTe₂/Si Photodiode Arrays

Abstract The market demand for optoelectronic devices is increasing, leading to a need for low‐cost, high‐performance image sensors that can operate effectively in challenging environments such as darkness and fog. The emerging 2D transition metal dichalcogenides (TMDs) have garnered significant interest due to their exceptional optoelectronic properties and compatibility with silicon (Si) complementary metal oxide semiconductor (CMOS) technology. However, the large‐scale synthesis of TMD films and uniform preparation of photodiode arrays remain challenging. This paper reports a synthesis method for heteroepitaxial growth of 2H‐ molybdeum diyelluride (MoTe₂) semiconducting films on 3D wafer‐level Si substrates. Using this method, arrays of 2H‐MoTe₂/Si heterojunction photodiodes are prepared that demonstrate excellent uniformity and 100% device yield. The photodiodes exhibit satisfactory optoelectronic properties, including a small dark current maintained within a range of 1–3 nA and a maximum responsivity of 521.1 mAW⁻¹ under near‐infrared light at 800 nm, with rise and fall times of less than 4 ms. To demonstrate the image‐sensing capabilities of the photodiode array under visible and near‐infrared (NIR) light illumination, a complete imaging system is designed.The MoTe₂/Si photodiode arrays examined in this study offer a practical solution for integrating Si‐based readout circuits and photodetector arrays on a single chip.