High-Performance Nonvolatile Write-Once-Read-Many-Times Memory Devices with ZnO Nanoparticles Embedded in Polymethylmethacrylate

A mixture of ZnO nanoparticles and polymethylmethacrylate was used as an active layer in a nonvolatile resistive memory device. Current-voltage characteristics of the device showed nonvolatile write-once-read-many-times memory behavior with a switching time on the order of μs. The device exhibited an on/off ratio of 10^4, retention time of >10^5 s, and number of readout of >4 × 10^4 times under a read voltage of 0.5 V. The emission, cross-sectional high-resolution transmission electron microscopy (TEM), scanning TEM-high angle annular dark field imaging, and energy dispersive x-ray spectroscopy elemental mapping measurements suggest that the electrical switching originates from the formation of conduction paths