Memristive device with highly continuous conduction modulation and its underlying physical mechanism for electronic synapse application

Emerging memristors can be used as artificial synapses for emulating memory and computational functions. In this work, inspired by the memristive properties of tantalum dioxide, we designed a memristor with a structure of TiN/Ta2O5-x/HfxZr1-xO2(x=0.5)/Pt (TTHZOP). The device conductance can be continuously tuned by adjusting the voltage pulse parameters (i.e., amplitude, width, and number) of voltage sweeps. Furthermore, for both of negative and positive parts, the current-voltage curves of the sweep cycle appear to better adjust the gradual distribution in successive twenty cycles. According to the fine fitting results of twenty positive and negative current-voltage (I-V) curves, the probability of an electron jumping over an energy barrier and the width of the energy barrier were analyzed in detail. It is found that the electron tunneling mechanism at the interface is responsible for gradual conduction change under successive external electrical stimulation consisting of both bulk and interface effects. The proposed TTHZOP memristor is a promising candidate in potential applications that mimic artificial biosynaptic adaptation and analog brain computation.

Automated summary

In this study, a novel memristor TTHZOP was designed based on the memristive properties of tantalum dioxide. The device conductance can be continuously tuned by adjusting voltage pulse parameters, and shows a gradual distribution adjustment in successive cycles.