New Research on Low-dimensional Avalanche Photodetector
High-sensitivity detection of few-photon or even single-photon technologies holds significant application prospects in fields such as low-light imaging, remote sensing and telemetry, as well as quantum communication. Among them, avalanche photodetectors (APD) have become an important direction in the field of optoelectronic device research due to their small size, high efficiency and easy integration. Signal-to-noise ratio (SNR) is an important indicator of APD Photodetector, which requires high gain and low dark current. The research on two-dimensional (2D) material van der Waals heterojunctions shows broad prospects in the development of high-performance APDs. Researchers from China selected the bipolar two-dimensional semiconductor material WSe₂ as the photosensitive material and carefully prepared the Pt/WSe₂/Ni structure APD Photodetector with the best matching work function to solve the inherent gain noise problem of traditional APD.
Researchers have proposed an avalanche photodetector based on the Pt/WSe₂/Ni structure, achieving highly sensitive detection of extremely weak light signals at the fW level at room temperature. They selected the two-dimensional semiconductor material WSe₂, which has excellent electrical properties, and combined it with Pt and Ni electrode materials to successfully develop a new type of avalanche photodetector. By precisely optimizing the work function matching among Pt, WSe₂ and Ni, a transport mechanism was designed that can effectively block dark carriers while selectively allowing photogenerated carriers to pass through. This mechanism significantly reduces the excess noise caused by carrier impact ionization, enabling the photodetector to achieve highly sensitive optical signal detection at an extremely low noise level.
This study demonstrates the crucial role of materials engineering and interface optimization in enhancing the performance of photodetectors. Through ingenious design of electrodes and two-dimensional materials, the shielding effect of dark carriers was achieved, significantly reducing noise interference and further improving detection efficiency. The performance of this detector is not only reflected in its photoelectric characteristics, but also has broad application prospects. With its effective blocking of dark current at room temperature and efficient absorption of photogenerated carriers, this photodetector is particularly suitable for the detection of weak light signals in fields such as environmental monitoring, astronomical observation, and optical communication. This research achievement not only provides new ideas for the development of low-dimensional material photodetectors, but also offers new references for the future research and development of high-performance and low-power optoelectronic devices.
Post time: Aug-27-2025