基于铁电材料的有机光电突触晶体管研究

Optoelectronic Artificial Synapse with Ferroelectric Material for Logical Functions and Modulation of Visual Memory

摘要:

模拟生物突触结构的设备是实现神经网络计算的可行方案之一,其中人工视网膜器件为机器视觉和图像识别的实现提供了有力支持。通过旋涂制备聚偏氟乙烯-三氟乙烯(P(VDF-TrFE) 制备铁电栅层,热蒸发酞菁铜(CuPc)作为半导体层,探究该晶体管模拟突触功能的光电响应。实验结果表明,该光电晶体管在625nm具有显著的光响应,其能够产生兴奋性突触后电流(EPSC)并实现短期可塑性到长期可塑性的转变以及高通滤波功能。利用剩余极化强度模拟了大脑学习过程中提前施加注意的行为。此外,以栅电压和光照作为独立输入逻辑信号,在单个晶体管中实现了“与”和“或”的布尔逻辑功能。上述结果表明, CuPc可以与铁电材料进行良好结合并制备出具有突触响应特点的光电晶体管,这为人工视网膜器件的开发提供了有机铁电器件的参考。

Abstract:

The use of devices that emulate biological synapses has gained recognition as a highly suitable alternative to the Von Neumann architecture. Artificial retinal devices provide advantageous contributions to the modeling of machine vision and image recognition. The goal of this research is to create artificial synaptic devices that are light-activated. This is achieved by using poly (vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE) as the ferroelectric layer and copper phthalocyanine(CuPc) as the semiconductor film. The researchers performed experiments aimed at replicating synapses, resulting in the generation of excitatory postsynaptic currents (EPSC), which allowed them to observe the synaptic plasticity characteristics and simulate memory responses to optical inputs. The experimental findings demonstrate that the polarization state of a ferroelectric material is influenced by the gate voltage, leading to a modulation of the decay rate of the photoresponsive current. The implementation of a high-pass filtering function was successfully accomplished. This device also enabled the realization of ‘AND’ and ‘OR’ Boolean logic functions by using gate voltage and light illumination as dual input logic signals.