Signal Filtering Enabled by Spike Voltage‐Dependent Plasticity in Metalloporphyrin‐Based Memristors

Abstract

Neural systems can selectively filter and memorize spatiotemporal information, thus enabling high‐efficient information processing. Emulating such an exquisite biological process in electronic devices is of fundamental importance for developing neuromorphic architectures with efficient in situ edge/parallel computing, and probabilistic inference. Here a novel multifunctional memristor is proposed and demonstrated based on metalloporphyrin/oxide hybrid heterojunction, in which the metalloporphyrin layer allows for dual electronic/ionic transport. Benefiting from the coordination‐assisted ionic diffusion, the device exhibits smooth, gradual conductive transitions. It is shown that the memristive characteristics of this hybrid system can be modulated by altering the metal center for desired metal–oxygen bonding energy and oxygen ions migration dynamics. The spike voltage‐dependent plasticity stemming from the local/extended movement of oxygen ions under low/high voltage is identified, which permits potentiation and depression under unipolar different positive voltages. As a proof‐of‐concept demonstration, memristive arrays are further built to emulate the signal filtering function of the biological visual system. This work demonstrates the ionic intelligence feature of metalloporphyrin and paves the way for implementing efficient neural‐signal analysis in neuromorphic hardware.

Novel Porphyrin‐Containing Polymer Based Memristor for Synaptic Plasticity Simulation

“…This voltage‐dependent characteristic is SVDP synaptic plasticity, which could be used to simulate neural habits and sensitization functions. [ 6 ] In order to simulate the learning‐forget‐relearning function, a 9 V learning pulse was applied to the device, the current value increased from 406 μA to 837 μA, and the amount of first learning and memory continued to increase. Then the device was applied a 3 V forgetting pulse, and the current value attenuated from 61 μA to 26 μA.…”

“…The PZnTPP‐SFX based SVDP memristor follows the space charge limited current (SCLC) model. [ 6 ] The I ‐ V curve at low voltage region is dominated by an almost trap‐free SCLC, the resistive state is induced to continuously transition to a higher resistive state. As the voltage increases, the I – V relationship agrees with trap‐controlled SCLC and the resistive state is decreased gradually.…”

“…Currently, reported memristive materials include metal‐oxide, chalcogenides, bioinspired materials and organic materials. [ 6‐8 ] Among them, organic materials show promising prospects on the development of high‐performance memristor due to their flexible synthesis, solution processability and the ability to prepare flexible devices. [ 9 ]…”

“…Inspired by biological processes such as photosynthesis and the transport and storage of oxygen by hemoporphyrin molecules, [ 21 ] our group has proposed a metalloporphyrin/oxide hybrid heterojunction memristor, in which the metalloporphyrin layer allows for dual electronic/ionic transport. [ 6 ] The device simulated the conventional synaptic plasticity, and presented a new control mode spike‐voltage dependent plasticity (SVDP). In this paper, we use polyporphyrin as the resistive switching layer.…”

Gridization‐Driven Mesoscale Self‐Assembly of Conjugated Nanopolymers into Luminescence‐Anisotropic Photonic Crystals

“…[19] Furthermore, bulk heterojunction is established to enhance power conversion efficiencies (≈18%) in solar cells; [21,22] uniform amorphous film is controlled to increase electroluminescence efficiencies (≈25%) in lightemitting diodes; [23] polycrystalline state is achieved to improve charge carrier mobility (1-10 cm 2 V -1 s -1 ) in field-effect transistors, [24,25] along with intelligent memory, [26] and memristor performances. [27] However, their optoelectronic performances lag far behind inorganic counterparts [28,29] such as GaN, ZnO, and so on. Until now, blue-emitters have suffered from the insufficient stability and short lifetime in organic light-emitting diode (OLED) display.…”