Effects of C-60 Concentration on the Storage Density in Nonvolatile Memory Devices Fabricated by Utilizing Hybrid Nanocomposites Consisting of C-60 Embedded in a Polymethyl Methacrylate Polymer Layer

Abstract

Nonvolatile memory devices based on a hybrid polymethyl methacrylate (PMMA) layer containing fullerene (C-60) were formed by using a spin coating method. Capacitance-voltage (C-V) measurements on Al/C-60 embedded in PMMA/p-Si (100) devices at 300 K showed a hysteresis with a large flatband voltage shift due to the existence of C-60 molecules, indicative of the charge storage in the C-60 molecules. The magnitude of the flatband voltage shift for the devices with an active layer consisting of PMMA and C-60 hybrid nanocomposites increased with increasing C-60 concentration. Operating mechanisms of the writing and the erasing processes for the Al/C-60 embedded in PMMA/p-Si devices are described on the basis of the C-V results.