摘要
Organic ultrathin crystals,comprising monolayers or a few molecular layers,exhibit outstanding optoelectronic properties and have shown great promise for constructing advanced functional neuromorphic devices.However,scalable growth of high-quality organic ultrathin crystals and their seamless concurrent integration with charge trapping layers for multi-mode neuromorphic devices,that required in future high-density neuromorphic integration,remain challenging.Here,we present a scalable one-step fabrication strategy based on solution shearing,where spontaneous vertical phase separation of a small-molecule/polymer(Ph-BTBT-10/PS)blend enables the simultaneous formation of high-quality ultrathin Ph-BTBT-10 crystals and an electret PS charge-trapping layer.The PS electret layer serves a dual function:it facilitates the formation of ultrathin,highly ordered Ph-BTBT-10 crystals;meanwhile,its gate-tunable electron-trapping capability enables dynamic switching between photo-switching and photo-synaptic modes within a single device.As a photodetector,the device exhibits exceptional performance,including a responsivity of 4.7×10^(4) A/W,specific detectivity of 2.2×10^(17) Jones,and photosensitivity of 1.5×10^(8).Under negative gate bias,light-triggered switching behavior enables logic gate demonstration,while under positive gate modulation,photonic synaptic behavior successfully emulates key biological functions,including excitatory postsynaptic current(EPSC),paired-pulse facilitation(PPF),short-term plasticity(STP)to long-term plasticity(LTP)transition,dynamic learning-forgetting processes,and image processing.Moreover,the system exhibits excellent compatibility with low-voltage flexible substrates and further demonstrates its application in low-consumption flexible neuromorphic devices.This work provides a scalable route toward high-performance,multifunctional neuromorphic optoelectronics based on organic ultrathin crystals,and advances the integration of flexible electronics and brain-inspired computing.
有机超薄晶体,由单层或几个分子层构成,因其固有的二维限域效应而展现出优异的光电特性,并在构建先进功能神经形态器件方面显示出巨大潜力.然而,面向未来神经形态器件的高密度集成需求,实现高质量有机超薄晶体的规模化生长并与电荷俘获层的同步无缝集成以构筑可控的多模式神经形态器件,仍具有挑战.本文基于溶液剪切法诱导小分子Ph-BTBT-10/聚合物PS共混溶液发生自发垂直相分离,实现了高质量超薄Ph-BTBT-10与驻极体电荷俘获层PS的同步集成.驻极体PS一方面可促进超薄、高度有序的Ph-BTBT-10晶体层的生长,另一方面其电子俘获特性的可通过栅压动态调控,从而允许在单个器件中实现光开关模式与光子突触模式的可控切换.作为光电探测器,该器件表现出卓越的性能,包括响应度达4.7×10^(4) A/W、比探测率达2.2×10^(17) Jones、光敏度达1.5×10^(8).基于负栅压的调制的光开关特性,其展示了在逻辑门的应用.基于正栅压调制的光子突触特性,它成功模拟了关键生物突触功能,如兴奋性突触后电流(EPSC)、成对脉冲易化(PPF)、短时程可塑性(STP)向长时程可塑性(LTP)的转变、动态学习-遗忘过程以及图像处理.此外,该体系与低压柔性基板具有优异的兼容性,并进一步展示了其在低功耗柔性神经形态器件的应用.本研究为基于有机超薄晶体的可控多模式神经形态光电子器件提供了可规模化的制备平台,并推动了柔性器件与类脑计算技术的交叉融合.
基金
supported by the National Key Research and Development Program of China(2022YFB3607500)
the National Natural Science Foundation of China(52373194,52403301,and 62274076)
the Haihe Laboratory of Sustainable Chemical Transformations.
