All Solution-Processed, Fully Transparent Resistive Memory Devices

We fabricated all-solution processed, fully transparent resistive random access memory (sol-TRRAM) with a configuration of ITO/GaZnO(GZO)/ITO. All layers, including an active layer and top and bottom ITO electrodes, were deposited on a glass substrate by either spin coating or inkjet printing using a sol-gel solution. Our sol-TRRAM was transparent, with 86.5% transmittance at 550 nm. An initial forming process is unnecessary for the production of transparent memory due to the presence of sufficient inherent nonlattice oxygen ions in the solution-processed GZO layer. The sol-TRRAM also showed reasonable bipolar resistance switching with a low operation current (<100 μA) and excellent cycle endurance properties (>300 cycles). The main conduction mechanism during the set process can be explained by the trap-controlled space-charge limited conduction, and the resistance change occurred by the modification of the potential barrier height because of the charge injection by Fowler-Nordheim tunneling.