Memory effect of ZnO nanocrystals embedded in an insulating polyimide layer

The memory effects of ZnO nanoparticles embedded in a polyimide (PI) matrix were investigated. Transmission electron microscopy images and selected area electron diffraction patterns showed that ZnO nanocrystals were created inside the PI layer. Capacitance-voltage (C-V) measurements on Al/PI/nanocrystalline ZnO∕PI∕p-Si structures at 300K showed a metal-insulator-semiconductor behavior with a flatband voltage shift due to the existence of the ZnO nanocrystals, indicative of trapping, storing, and emission in the electrons in the ZnO nanocrystals. Possible electronic structures corresponding to the writing and erasing operations for the Al/PI/nanocrystalline ZnO∕PI∕p-Si device are described on the basis of the C-V results.