For applications such as artificial intelligence and humanoid robotics, efficient and multifunctional vision systems must simultaneously offer high-speed photodetection (photodetector, PD) and brain-inspired visual sensing–memory capabilities (neuromorphic vision sensor, NVS). However, existing approaches often rely on more complex device architectures or fabrication processes, making it difficult for a single device to achieve dual-mode switching while balancing integration density and manufacturing complexity.
To address this bottleneck, the team of Prof. Guisheng Zou, Assoc. Prof. Lei Liu, and Assistant Researcher Jinping Huo from the Institute of Forming and Manufacturing Engineering, Department of Mechanical Engineering, Tsinghua University, recently proposed an innovative Microzone Femtosecond Laser Deposition (M-FLD) strategy. By focusing a femtosecond laser to ablate a microscale two-dimensional black phosphorus (BP) target, the team achieved in situ, localized deposition of BP nanoparticles onto designated regions of the device and constructed a 0D/2D heterostructure with a MoS2 nanofilm channel. By further employing an h-BN nanomask to selectively protect and confine the deposition region, they built a spatially asymmetric 0D-BP/2D-MoS2 structure, providing the structural basis for dual-mode optoelectronic conversion.
Figure 1. Fabrication of M-FLD and the dual-mode optoelectronic device
In terms of the device operating mechanism, this spatially asymmetric structure endows the device with markedly different optical responses under different bias directions. By reversing the direction of Vds, the device can switch reversibly between PD mode and NVS mode, thereby avoiding the integration burden associated with extra terminals or complex gating. The device can sense high-frequency optical signals up to 3030 Hz, with an optical energy consumption of only 191.2 pJ per event, and achieves a recognition accuracy of 96.20% in simulations of the MNIST handwritten digit recognition task.
Figure 2. Applications of the dual-mode optoelectronic device
According to the research team, for next-generation humanoid intelligent vision and highly integrated optoelectronic systems, the combination of “microzone in situ fabrication + reversible dual-mode switching within a single device” provides a new route toward high-performance, low-power neuromorphic optoelectronic devices with scalable potential.
The related study, titled “Dual-mode 0D/2D Spatial Asymmetry Optoelectronic Device Enabled by in situ Microzone Femtosecond Laser Deposition,” was published in Light: Science & Applications, a Springer Nature journal (IF 23.4 and one of the leading journals in optics). Zehua Li, a 2022 PhD student in the Department of Mechanical Engineering at Tsinghua University, is the first author; Prof. Guisheng Zou is the second author; and Assoc. Prof. Lei Liu and Assistant Researcher Jinping Huo are the co-corresponding authors. Postdoctoral researchers Bin Feng and Tianming Sun, Yu Xiao (Shanghai Jiao Tong University), Jiali Huo (National University of Singapore), and PhD student Jin Peng also contributed to this work. The research was supported by the National Natural Science Foundation of China, the Beijing Natural Science Foundation, and other funding programs.
Link to the paper: https://doi.org/10.1038/s41377-026-02195-8
