Synaptic Characteristics of an Ultrathin Hexagonal Boron Nitride (h‐BN) Diffusive Memristor

Abstract

A nano‐sized two‐terminal memristor exhibiting volatile threshold switching (TS) is a promising candidate for the emulation of biological synaptic functions to realize efficient neuromorphic computing systems. The Ca2+ dynamics play a vital role in generating a temporal response for neural functions by changing the synaptic weight of biological synapses. Herein, a thinnest synaptic device is fabricated demonstrating drift dynamics of Ag+ migration through the exfoliated h‐BN sheets, which emulates neuromorphic computing operations. The TS characteristics with a large ION/OFF up to ≈105 lead to bio‐synaptic applications, including short‐term and long‐term memory. The experimental realization of the synaptic behavior is demonstrated with paired‐pulse facilitation (PPF), spike‐rate‐dependent plasticity (SRDP), and transition from short‐term plasticity (STP) to long‐term plasticity (LTP). The transition from STP to LTP in this synaptic device verifies the Atkinson and Shiffrin psychological model of human brain learning experimentally. The input pulses with different spike‐times are used to replicate the synaptic functionalities. The two‐terminal diffusive memristors constructed with thin sheets of 2D‐flexible h‐BN resistive materials may lead to flexible neuromorphic devices for biological applications.

p‐GeSe/n‐ReS2 Heterojunction Rectifier Exhibiting A Fast Photoresponse with Ultra‐High Frequency‐Switching Applications

“…[1][2][3][4] Several practical devices such as field-effect transistors (FETs), solar cells, logic circuits, memories, diodes, and photodetectors have been prepared based on single-or van der Waals stack of two same or different TMDs for effective operations and controlled functionalities. [5,6] The van-der walls heterostructures made up of single-layer or multilayer stacking of TMDs materials are considered more flexible and efficient due to their sharp interfaces. [7] Among all these devices, diodes have been found to be the most intriguing component in recent electronics and thus intensively pursued particularly in two van der Waals heterostructures designs, e.g., p-n and p-i-n where, "p-" denotes p-type semiconductor, "n-" is an n-type semiconductor, and "i" is an insulating layer.…”

A Synaptic Transistor Based on Monolayer Monocrystalline‐MoS2 for Neuromorphic Applications

“…[3,37,38] Importantly, the transformation from STP to LTP can be achieved by continuous stimulation and training, which is consistent with a multistore model for the memory behavior proposed by Atkinson and Shiffrin. [2,39] As shown in Figure 4d, the peak PSC reaches %4.3 μA by applying 10 pluses with a voltage amplitude of 6 V. Then the PSC almost decays back to initial current after 20 s, demonstrating the STP characteristic of the device. When spike amplitude is 8 V, the peak PSC is %7.7 μA for 10 pluses.…”

Optoelectronic Synapses Based on Photo‐Induced Doping in MoS2/h‐BN Field‐Effect Transistors

“…Because of the poor inter‐plane conductivities of 2D channel materials and h‐BN dielectrics, and the van der Waals energy barrier between them, it is possible to realize stable and retainable synaptic devices in 2D FETs with h‐BN as the gate dielectric layers. [ 33–35 ]…”