Artificial 2D van der Waals Synapse Devices via Interfacial Engineering for Neuromorphic Systems

Abstract

Despite extensive investigations of a wide variety of artificial synapse devices aimed at realizing a neuromorphic hardware system, the identification of a physical parameter that modulates synaptic plasticity is still required. In this context, a novel two-dimensional architecture consisting of a NbSe2/WSe2/Nb2O5 heterostructure placed on an SiO2/p+ Si substrate was designed to overcome the limitations of the conventional silicon-based complementary metal-oxide semiconductor technology. NbSe2, WSe2, and Nb2O5 were used as the metal electrode, active channel, and conductance-modulating layer, respectively. Interestingly, it was found that the post-synaptic current was successfully modulated by the thickness of the interlayer Nb2O5, with a thicker interlayer inducing a higher synapse spike current and a stronger interaction in the sequential pulse mode. Introduction of the Nb2O5 interlayer can facilitate the realization of reliable and controllable synaptic devices for brain-inspired integrated neuromorphic systems.

Low Power MoS2/Nb2O5 Memtransistor Device with Highly Reliable Heterosynaptic Plasticity

“…The Nb 2 O 5 with a large amount of oxygen vacancies functions as a charge trapping layer between the MoS 2 channel and the Al 2 O 3 high‐k dielectric. [ 58 ] We found that even the MoS 2 transistor without the Nb 2 O 5 layer caused a small hysteresis behavior, as intrinsic defects in the polycrystalline MoS 2 film and extrinsic interfacial defect states between the MoS 2 and high‐k dielectric still exist (Figure S6, Supporting Information). [ 34,59 ] Thus, gate pulse stimuli can also contribute to the conductance change in our MoS 2 /Nb 2 O 5 memtransistor, which is referred to as gate‐tuned synaptic plasticity (Figure 5b).…”

Promising Materials and Synthesis Methods for Resistive Switching Memory Devices: A Status Review

“…Figure b-iii displays the back-gate arrangement of the WSe 2 -based electronic synapse transistor which is imitating the functionalities of the biological synapse. This study demonstrated the realization of synaptic devices for brain-inspired integrated neuromorphic applications …”

“…165 This study demonstrated the realization of synaptic devices for brain-inspired integrated neuromorphic applications. 166 Moreover, Lee et al have fabricated a few-layer tungsten diselenide (WSe 2 )-based device that has applications in the field of neuromorphic computing. It was noticed that the programmed functions can be deleted by exterior conditions (ultraviolet irradiation or temperature), which are necessary for electronic safety measures.…”

Preparation and Properties of 2D Materials

“…Finding a physical parameter that precisely modulates synaptic plasticity is particularly required. Following this motivation, Kim et al proposed a novel two-dimensional transistor architecture consisting of a NbSe 2 /WSe 2 /Nb 2 O 5 heterostructure [11]. NbSe 2 , WSe 2 , and Nb 2 O 5 function as a metal electrode, an active channel, and a conductance-modulating layer, respectively.…”