Effect of Annealing Temperature on Memristive Characteristics of Cu/Parylene–MoOx/ITO Structures

Organic and hybrid memristors are attractive for use as synapses in bio-like neuromorphic computing systems. Nanocomposite structures based on poly-p-xylylene (PPX) nanoparticles with molybdenum oxide exhibit promising memristive properties. Annealing of PPX-based nanocomposite structures after synthesis significantly improves their memristive characteristics, but a detailed study of the effect of annealing temperature on memristive structures has not been conducted. In this paper, the influence of annealing temperature (from 150 to 400°C) on the structural features and electrical properties of the Cu/PPX–MoOx/ITO structure was studied in detail. Thermal annealing at temperatures of 150, 200 and 250°C leads to a gradual compaction of the PPX matrix, which causes a slight increase in resistive switching voltages and a slight decrease in the resistance window, worsens the endurance to cyclic switching and the stability of resistive states, while a decrease in the spread of memristive characteristics is observed. Temperatures of 300°C and above lead to thermal destruction of PPX, and at temperatures above 350°C, crystallization of MoOx occurs. It is found that the optimal annealing temperature for memristive structures is Cu/PPX–MoOx/ITO is in the range of 150–200°C.