The development of optical memory with attractive features such as long-lasting, nonvolatile, high-speed, and low-energy consumption is vitally important in the information age. Owing to these advantages, optical memory has been popular for more 10 years. Recently, flexibility has become desirable for the application of wearable devices and smart artificial intelligence; for conventional optical memory, this is still difficult to achieve. To combine optical memory with soft materials, this study presents a flexible and photoelectronic switchable multilevel memory device with long-lasting nonvolatile properties. On the basis of the integration of nanoscale (graphene nanoflakes) and macroscale graphene heterojunctions, a device achieves switchable memory states up to 196 distinct levels under the illumination of lasers with different wavelengths. The photoelectronic memory device can be written optically and erased by both optical and electric methods. Additionally, the device possesses several unique features including a low working bias of 0.5 V, nonvolatility for over 10 000 s, and mechanical stability for more than 10 000 bending cycles. Notably, in previous studies, polymers with poor mobility were used as a conducting channel, which can greatly limit the amplitude of the light-induced switching ratio and electrical performance. In stark contrast, in our device, the graphene layer with the mobility exceeding several orders of magnitude was used to serve as a conducting channel, enabling one to overcome the existing shortcoming. Our approach therefore not only provides an alternative paradigm for the development of photoelectronic memory but also holds great promise for practical applications due to its compatibility with current technologies.

中文翻译：

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纳米和大规模石墨烯异质结构的集成，用于柔性和多级非易失性光电存储

具有持久性，非易失性，高速和低能耗等诱人功能的光学存储器的开发在信息时代至关重要。由于这些优点，光学存储器已经流行了十多年了。近来，对于可穿戴设备和智能人工智能的应用，灵活性已成为人们所期望的。对于常规的光学存储器，这仍然很难实现。为了将光存储器与软材料结合起来，本研究提出了一种具有持久非易失性的柔性和光电可切换多级存储设备。基于纳米级（石墨烯纳米薄片）和大型石墨烯异质结的集成，在不同波长的激光照射下，器件可实现高达196个不同级别的可切换存储状态。光电存储器件可以通过光学和电学方法进行光学写入和擦除。此外，该器件还具有几个独特的功能，包括0.5 V的低工作偏置，超过10000 s的非易失性以及超过10000次弯曲循环的机械稳定性。值得注意的是，在先前的研究中，将流动性较差的聚合物用作导电通道，这会大大限制光致开关比和电性能的幅度。与之形成鲜明对比的是，在我们的设备中，迁移率超过几个数量级的石墨烯层被用作导电通道，从而克服了现有缺陷。