Ultrasensitive Memristive Synapses Based on Lightly Oxidized Sulfide Films
Ultrasensitive Memristive Synapses Based on Lightly Oxidized Sulfide Films
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基于轻度氧化硫化物薄膜的超灵敏忆阻突触
DOI：
10.1002/adma.201606927
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发表时间：
2017-06-27
影响因子：
29.4
通讯作者：
Zhuge, Fei
中科院分区：
文献类型：
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作者：
Hu, Lingxiang;Fu, Sheng;Zhuge, Fei
对于生物突触，高灵敏度对于快速准确地传递信息至关重要。与生物突触相比，记忆突触对电刺激的敏感性要低得多，因为诱导突触可塑性需要更高的电压。然而，提高突触设备的敏感度却鲜有人关注。这里发现，基于轻度氧化的ZnS薄膜的电化学金属化存储单元表现出高度可控的记忆开关，其设置电压为几毫伏，这可能起源于两层结构的ZnS薄膜，即轻微氧化和未氧化的层，其中，由于这两层中不同的离子传输速率，灯丝的破裂/恢复被限制在厚度为几纳米的两层界面区域。在这种装置的基础上，实现了一种超灵敏的记忆突触，通过施加几毫伏的幅度的电刺激来模拟突触的短期可塑性和长期增强功能，其敏感性远远超过生物突触。记忆和遗忘的动态过程是通过5x5记忆突触阵列来模拟的。此外，超低的工作电压除了降低工作电流和脉冲宽度外，还为突触设备相对较高的能耗提供了另一种有效的解决方案。
For biological synapses, high sensitivity is crucial for transmitting information quickly and accurately. Compared to biological synapses, memristive ones show a much lower sensitivity to electrical stimuli since much higher voltages are needed to induce synaptic plasticity. Yet, little attention has been paid to enhancing the sensitivity of synaptic devices. Here, electrochemical metallization memory cells based on lightly oxidized ZnS films are found to show highly controllable memristive switching with an ultralow SET voltage of several millivolts, which likely originates from a two-layer structure of ZnS films, i.e., the lightly oxidized and unoxidized layers, where the filament rupture/rejuvenation is confined to the two-layer interface region several nanometers in thickness due to different ion transport rates in these two layers. Based on such devices, an ultrasensitive memristive synapse is realized where the synaptic functions of both short-term plasticity and long-term potentiation are emulated by applying electrical stimuli several millivolts in amplitude, whose sensitivity greatly surpasses that of biological synapses. The dynamic processes of memorizing and forgetting are mimicked through a 5 x 5 memristive synapse array. In addition, the ultralow operating voltage provides another effective solution to the relatively high energy consumption of synaptic devices besides reducing the operating current and pulse width.