Effect of electrode area on resistive switching behavior in translucent solution-processed AlOx based memory device

A translucent resistance random access memory (RRAM) device with Ag/AlOx/indium tin oxide (ITO) stack grown on a glass substrate were fabricated. The effect of the electrode diameter from 0.1 mm to 0.3 mm on resistive switching (RS) characteristics was investigated through a systematic and comprehensive investigation. The device shows reproducible bipolar RS behavior with satisfied uniformity, excellent retention and endurance. The sample with the diameter of 0.3 mm demonstrates frequent gradual switching characteristics during the current-voltage (I–V) measurement, a symmetrical and centralized voltage/resistance distribution as well as a minimum resistance ratio. As a result, there can be some tradeoffs among the parametric dispersion, power consumption and resistance ratio for the Ag/AlOx/ITO device with different electrode areas. Moreover, the conduction mechanisms of the Ag/AlOx/ITO device with the minimum and maximum diameters were found to be Ohmic conduction behavior in ON state, whereas the trap-controlled space charge limited conduction (SCLC) mechanism and Poole-Frenkel (PF) emission in OFF state, respectively. The multi-level conductance modulation and a preliminary simulation of synaptic plasticity were conducted, which confirmed the potentials of the Ag/AlOx/ITO device in the multi-value storage and synaptic learning.