A Digital–Analog Integrated Memristor Based on a ZnO NPs/CuO NWs Heterostructure for Neuromorphic Computing

Abstract

As an emerging electronic device, a memristor facilitates the realization of neuromorphic computing systems. However, high-performance neuromorphic computing systems require not only robust analog memristors but also digital memristors with complementary functions. Here, a digital–analog integrated memristor based on Al/ZnO NPs/CuO NWs/Cu is proposed and demonstrated. First, the electrical properties of the CuO NWs based device are investigated, which exhibit a write-once-read-many-times (WORM) performance. Then, typical bipolar resistive switching behaviors are realized by spin-coating the ZnO NPs to form an Al/ZnO NPs/CuO NWs/Cu based memristor. Through tuning of the applied voltage, an abrupt-to-gradient transition of conductance is achieved in situ. Several analog behaviors, such as long-term potentiation/depression (LTP/LTD), and paired-pulse facilitation/depression (PPF/PPD) are effectively emulated by applying a series of specified electrical measurements to the memristor, which proves the achievement of a digital–analog integrated memristor. Furthermore, on the basis of the LTD and LTP behaviors of the memristor, neural network simulations for handwritten recognition are implemented. The results reveal high recognition accuracies of up to 93%, which are close to the performances for ideal memristors.

A review of memristor: material and structure design, device performance, applications and prospects

“…Binary oxides have a simple composition, high stability, low cost, simple preparation process, and are compatible with the traditional CMOS process. They include TiO x [ 46–50 ], SiO x [ 51–53 ], AlO x [ 54 ], NiO x [ 55 , 56 ], CuO x [ 57 , 58 ], ZnO x [ 59 , 60 ], HfO x [ 61 , 62 ], TaO x [ 63 , 64 ], WO x [ 65 , 66 ], ZrO x [ 67 , 68 ], SnO x [ 69 ] etc. In particular, HfO x and TaO x are the most promising binary oxides due to their sub-ns operation speed and ultimate endurance of more than 10 10 cycles [ 70 ].…”

“…To simulate synapses, the memristor exhibit a simulated switching behavior that requires a gradual SET and RESET processes rather than an abrupt one [ 180 ]. Recently, some research groups have investigated synaptic properties using materials based on ion migration or electrochemical reduction reactions, such as TiO x [ 181 ], HfO x [ 182 ], TaO x [ 183 , 184 ], ZnO x [ 57 , 60 ], organic [ 185–187 ] et al Qiao et al prepared a memristor base onC 12 -BTBT. As shown in Figure 8(a) , a positive voltage pulse with the assistance of UV light irradiation (1.35 mW cm −2 ) was applied to the memristor to trigger the excitatory postsynaptic currents (EPSC) [ 188 ].…”

Applications of MXenes in human-like sensors and actuators

“…The data retention can be extended with the assistance of resistive random access memory [310] and neuromorphic computing [311]. Indeed, the interfaces could be built between data acquisition [312] (at electronic skins) and transmission to processing devices (for computing).…”

Optoelectronic Memristive Synapse Behavior for the Architecture of Cu2ZnSnS4@BiOBr Embedded in Poly(methyl methacrylate)

“…The current explosion of information technologies has drastically expanded the gap between conventional computation capacities and current huge computing needs. Brain-inspired neuromorphic calculation patterns have been considered as an ideal solution to realize parallel data processing with both excellent precision and storage capability. − The memristor, a metal/medium/metal sandwich structured two-terminal resistive switching device, has become the most promising candidate to serve as artificial synapses in neuromorphic computing owing to its exhibited multiple synaptic functionalities, such as long-term potentiation/depression (LTP/LTD) plasticity, long-/short-term memory (LTM/STM), spike-timing-dependent plasticity (STDP), and paired-pulse facilitation (PPF). , As the decisive constitute for memristor performance, different kinds of oxides (AlO x , TiO 2 , ZnO), − sulfides (Cu 9 S 5 , MoS 2 , Ag 2 S), − nitrides (BN, SiN), − and composite structural materials (WS 2 /MoS 2 , PdSeO x /PdSe 2 , ZnO/CuO) − have been applied to resistive media to realize superior optoelectronic regulated memristor performance. Although stable and durable regulatory resistance switching characterizations can be achieved with great effort using available memristors, it is still challenging to endow them with electrical- and light-induced synaptic behaviors mimicing biological synapses.…”