A Self-Rectifying Synaptic Memristor Array with Ultrahigh Weight Potentiation Linearity for a Self-Organizing-Map Neural Network

Hengjie Zhang; Biyi Jiang; Chuantong Cheng; Beiju Huang; Huan Zhang; Run Chen; Jiayi Xu; Yulong Huang; Hongda Chen; Weihua Pei; Yang Chai; Feichi Zhou

doi:10.1021/acs.nanolett.2c03624

A Self-Rectifying Synaptic Memristor Array with Ultrahigh Weight Potentiation Linearity for a Self-Organizing-Map Neural Network

Nano Lett. 2023 Apr 26;23(8):3107-3115. doi: 10.1021/acs.nanolett.2c03624. Epub 2023 Apr 12.

Authors

Hengjie Zhang^{1

2

3}, Biyi Jiang^{1

4}, Chuantong Cheng^{2

3}, Beiju Huang^{2

3}, Huan Zhang^{2

3}, Run Chen^{2

3}, Jiayi Xu¹, Yulong Huang^{2

3}, Hongda Chen^{2

3}, Weihua Pei^{2

3}, Yang Chai⁴, Feichi Zhou¹

Affiliations

¹ School of Microelectronics, Southern University of Science and Technology, Shenzhen 518000, People's Republic of China.
² The State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People's Republic of China.
³ College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
⁴ Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, People's Republic of China.

PMID: 37042482
DOI: 10.1021/acs.nanolett.2c03624

Abstract

Two-terminal self-rectifying (SR)-synaptic memristors are preeminent candidates for high-density and efficient neuromorphic computing, especially for future three-dimensional integrated systems, which can self-suppress the sneak path current in crossbar arrays. However, SR-synaptic memristors face the critical challenges of nonlinear weight potentiation and steep depression, hindering their application in conventional artificial neural networks (ANNs). Here, a SR-synaptic memristor (Pt/NiO_x/WO_3-x:Ti/W) and cross-point array with sneak path current suppression features and ultrahigh-weight potentiation linearity up to 0.9997 are introduced. The image contrast enhancement and background filtering are demonstrated on the basis of the device array. Moreover, an unsupervised self-organizing map (SOM) neural network is first developed for orientation recognition with high recognition accuracy (0.98) and training efficiency and high resilience toward both noises and steep synaptic depression. These results solve the challenges of SR memristors in the conventional ANN, extending the possibilities of large-scale oxide SR-synaptic arrays for high-density, efficient, and accurate neuromorphic computing.

Keywords: image background filtering; orientation recognition; self-organizing-map (SOM) neural network; self-rectifying synaptic memristor array; ultrahigh weight potentiation linearity.