Bi-stable switching behaviors of ITO/EVA:ZnO NPs/ITO transparent memory devices fabricated using a thermal roll lamination technique

Abstract

This research reported the transparent non-volatile write-once-read-many-times (WORM) memory behaviors of memory devices based on zinc oxide nanoparticles (ZnO NPs) embedded in an insulating poly(ethylene-co-vinyl acetate) (EVA), sandwiched between two ITO-coated flexible polyethylene naphthalate (PEN) substrates. The memory devices were fabricated employing a thermal roll lamination technique with the laminated-structure of PEN/ITO/EVA:ZnO NPs/ITO/PEN. The average transmittance of the laminated memory device was over 70% for an optical visible range of 400–800 nm. The maximum ON/OFF current ratio for the memory device was about 103. In addition, a reliability study for continuous read operations in a long time memory device is presented. The conductance switching mechanisms of the laminated memory device were analyzed using theoretical models on the basis of the experimental data.