Multifunctional Two-Terminal Optoelectronic Synapse Based on Zinc Oxide/Poly(3-hexylthiophene) Heterojunction for Neuromorphic Computing

Abstract

With the advantages of wide bandwidth, low power consumption, high propagation speed, and excellent interconnectivity, the light-tunable synapse is regarded as one of the most promising candidates to pave the way for constructing neuromorphic computing and overcoming the von Neumann bottleneck. Herein, an optoelectronic synaptic memristor based on zinc oxide/poly(3-hexylthiophene) (ZnO/ P3HT) heterojunction is fabricated via a simple two-step spin coating process. The prepared device can simulate typical neuromorphic manners, such as excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), the transformation from short-term plasticity (STP) to long-term plasticity (LTP), and "learning-experience" behavior by modulating the applied light pulses. In addition to the optoelectronic synaptic behaviors, our device incorporates light logic functions ("AND" and "OR" operations) and optical information detection and memory functions analogous to those in the human's visual recognition memory system.

Synaptic and Gradual Conductance Switching Behaviors in CeO2/Nb–SrTiO3 Heterojunction Memristors for Electrocardiogram Signal Recognition

“…The results show that the shorter the interval between two pulses, the greater the conductance change of the memristor. Besides, the PPF curve is fitted according to eq normalΔ W = ( G 2 − G 1 ) / G 1 × 100 % PPF = ( G 2 − G 1 ) / G 1 × 100 % = C 1 exp ( − t / τ 1 ) + C 2 exp ( − t / τ 2 ) where G 1 and G 2 are, respectively, the conductance values after the first and second pulses, and t is defined as the pulse interval.…”

Advanced Optoelectronic Devices for Neuromorphic Analog Based on Low‐Dimensional Semiconductors

“…Then, the trapped carriers can gradually restore the device to the initial state through detrapping behavior. [ 31,85,87–91 ]…”

“…Then, the trapped carriers can gradually restore the device to the initial state through detrapping behavior. [31,85,[87][88][89][90][91] Liang et al [92] reported a high-performance optoelectronic synapse transistor based on InP/ZnSe quantum dots (QDs) and n-type SnO 2 heterostructure (Figure 7a). This special heterojunction improves the separation efficiency of photoexcited charges, leading to high photoresponsivity and tunable synaptic weight changes.…”

Emerging photoelectric devices for neuromorphic vision applications: principles, developments, and outlooks

“…This study effectively emulates superior visual perception and visual memory performance. Zhao et al [ 203 ] built an array using the zinc oxide/poly(3-hexylthiophene) (ZnO/P3HT) optoelectronic heterojunction memristor. Figure 12(d) shows the current attenuation of input images obtained by varying the wavelength, intensity, and frequency of the light.…”

“…(d) Input image encoded by light of different wavelengths, intensities and frequencies for ZnO/P3HT optoelectronic heterojunction memristor. Reproduced by permission from [ 203 ], copyright [2022, American Chemical Society].…”