Nonvolatile memory and opto-electrical characteristics of organic memory devices with zinc oxide nanoparticles embedded in the tris(8-hydroxyquinolinato)aluminum light-emitting layer

The nonvolatile organic memory devices based on the tris(8-hydroxyquinolinato)aluminum (Alq3) emitting layer embedded with zinc oxide nanoparticles (ZnO-NPs) are reported. An external bias is used to program the ON and OFF states of the device that are separated by a four-orders-of-magnitude difference in conductivity. The conductivity switching is associated with a decrease in bulk resistance and an increase in dielectric constant of the active material. These nanoparticles behave as the charge trapping units, which enable the nonvolatile electrical bistability when biased to a sufficiently high voltage. Moreover, it is found that the location of the ZnO-NPs could affect the memory and opto-electrical characteristics of the devices, which can be attributed to the influence of the ZnO-NPs and diffused Al atoms in the bulk of the Alq3 layer.