The bionic optic nerve can mimic human visual physiology and is a future treatment for visual disorders. Photosynaptic devices could respond to light stimuli and mimic normal optic nerve function. By modifying (Poly(3,4-ethylenedioxythio-phene):poly (styrenesulfonate)) active layers with all-inorganic perovskite quantum dots, with an aqueous solution as the dielectric layer in this paper, we developed a photosynaptic device based on an organic electrochemical transistor (OECT). The optical switching response time of OECT was 3.7 s. To improve the optical response of the device, a 365 nm, 300 mW·cm -2 UV light source was used. Basic synaptic behaviors such as postsynaptic currents (0.225 mA) at a light pulse duration of 4 s and double pulse facilitation at a light pulse duration of 1 s and pulse interval of 1 s were simulated. By changing the way light stimulates, for example, by adjusting the intensity of the light pulses from 180 to 540 mW·cm -2, the duration from 1 to 20 s, and the number of light pulses from 1 to 20, the postsynaptic currents were increased by 0.350 mA, 0.420 mA, and 0.466 mA, respectively. As such, we realized the effective shift from short-term synaptic plasticity (100 s recovery of initial value) to long-term synaptic plasticity (84.3% of 250 s decay maximum). This optical synapse has a high potential for simulating the human optic nerve.
仿生视神经可以模拟人类的视觉生理机能，有潜力成为未来视觉障碍疾病的治疗手段。光突触器件能够对光刺激做出响应，模拟正常视神经功能。本文以全无机钙钛矿量子点（CsPbBr 3 QDs）修饰聚（3,4-亚乙二氧基噻吩）-聚（苯乙烯磺酸）（PEDOT∶PSS）有源层，以水溶液为电解质，开发了一种基于有机电化学晶体管（OECT）的光突触器件。该OECT器件的光开关响应时间为3.7 s，为了提高器件的光响应，采用365 nm、300 mW·cm −2的紫外光源，模拟光脉冲在4 s持续时间下的突触后电流（0.225 mA），以及光脉冲持续时间为1 s且脉冲间隔1 s条件下的双脉冲易化等基本突触行为。该光突触器件通过改变光刺激的方式，即通过调节光脉冲的强度从180～540 mW·cm −2，持续时间从1～20 s，以及光脉冲数从1～20，使得突触后电流分别增加了0.350、0.420、0.466 mA，有效地实现了短期突触可塑性（100 s恢复初始值）到长期突触可塑性（250 s衰减了最大值的84.3%）的转变。该光突触在模拟人类视神经方面具有一定的潜力。.
Keywords: Optical synapse; Organic electrochemical transistors; Perovskite quantum dot.