Highly Uniform Silver Ion Memristors With Ultralow Leakage Current for Constructing Homogeneously Spiking LIF Neurons

The stable and threshold-friendly electrochemical-metallization-based threshold switching (TS) memristors are promising candidates to build artificial leaky integrate-and-fire (LIF) neurons for neuromorphic computing. In this work, Ag/Al
$_{\text{2}}$
O
$_{\text{3}}$
/HfO
$_{\text{2}}$
/TiN memristors have been fabricated with small
V

$_{\text{th}}$
/
V

$_{\text{h}}$
variation coefficients of 0.021 and 0.051, a large selectivity (10
$^{\text{6}}$
), and ultralow leakage current (100 fA). The excellent volatile properties can be attributed to the insertion of a 2-nm Al
$_{\text{2}}$
O
$_{\text{3}}$
buffer layer, and the high uniformity of
V

$_{\text{th}}$
/
V

$_{\text{h}}$
causes homogeneous spiking behavior for LIF neurons. Moreover, spiking neural network (SNN) based on the memristor array is fabricated for image classification with a recognition accuracy of 93.2%, which provides guidelines for constructing stable and high-precision SNN systems by Ag
$^{+}$
ion-based artificial neurons.