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中国物理学会期刊

基于负光电导效应的PtSe2光电突触器件机理特性与感存算功能

CSTR: 32037.14.aps.74.20250403

Mechanism, characteristics and sensing, storage and computing function of PtSe2 photoelectric synaptic devices based on negative photoconductivity effect

CSTR: 32037.14.aps.74.20250403
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  • 具有感存算一体的高性能光电突触器件对于开发神经形态视觉系统(NVS)至关重要. 本文制备了具有负光响应的PtSe2光电突触器件, 测试了该器件在光脉冲刺激下呈现出抑制性突触后电流, 同时实现了光学可调的突触行为, 包括双脉冲易化、短程可塑性、长程可塑性. 此外, 器件表现出对光持续时间的依赖性, 模拟3×3传感器阵列展示和验证了图像原位传感和存储功能. 利用28×28器件阵列结合人工神经网络, 实现了视觉信息的集成感知-存储-预处理功能, 实验结果表明, 预处理后(去噪后)的图像在经过100个epoch训练后达到91%的准确率. 最后, 利用器件对不同波长光照所响应的负光电导不同, 建立了光电突触逻辑门: 或非(“NOR”)、与非(“NAND”)和异或(“XOR”), 实现了图像逻辑运算. 研究结果有力地推进了PtSe2负光响应光电突触器件的应用, 为更加集成和高效的NVS铺平道路.

     

    Machine vision, serving as the “eyes” of artificial intelligence (AI), is one of the key windows for AI to acquire external information. However, traditional machine vision relies on the Von Neumann architecture, where sensing, storage, and processing are separated. This architecture necessitates constant data transfer between different units, inevitably leading to high power consumption and latency. To address these challenges, a PtSe2 photosynaptic device with negative light response is prepared. The device shows an inhibitory postsynaptic current (IPSC) under light pulse stimulation, and achieves optically tunable synaptic behaviors, including double pulse facilitation (PPD), short-range plasticity (STP), and long-range plasticity (LTP). In addition, by using a 3 × 3 sensor array, the device exhibits dependence on light duration, and the image in-situ sensing and storage functions are demonstrated and verified. By using 28 × 28 device array combined with artificial neural network (ANN), the integrated perception-storage-preprocessing function of visual information is realized. The experimental results show that the image after preprocessing (denoising) is trained for 100 epochs, and the accuracy rate reaches 91%. Finally, lasers with two representative wavelengths of 405 nm and 532 nm are chosen as the light sources in the experiment, and the I-V characteristic curve changes most under the blue light pulse of 450 nm, which is because the blue light has higher photon energy to produce negative light effect. Based on the different photocurrents of the device responding to different wavelengths of light, the photoelectric synaptic logic gates ‘NOR’, ‘NAND’ and ‘XOR’ are established, which enables image processing functions such as dilation, erosion and difference recognition. The device’s power consumption is calculated to be 0.111 nJ per spike. The research results indicate that the negative photoconductivity of PtSe2 has great potential in simplifying information processing and effectively promoting applications, which will help promote more integrated and efficient NVS.

     

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