High-Performance Flexible Organic Nano-Floating Gate Memory Devices Functionalized with Semiconducting Nanoparticles

Abstract

Transistor-type nano-floating gate memory (NFGM) devices have recently attracted great interest because of their unique and compatible characteristics as suitable platforms for integrated circuits. Their excellent memory properties with inexpensive fabrication processes make NFGM devices highly promising for the next-generation data storage devices. Herein, novel nonvolatile NFGM devices utilizing semiconducting cobalt ferrite (CoFe2O4) nanoparticles (NPs) as the charge trap sites with p-type semiconductor, pentacene as active layer on flexible and transparent polymer substrates as well as on conventional silicon wafers have been prepared. Monodisperse CoFe2O4 NPs, which were synthesized in solution from cheap and nontoxic metal-oleate complex precursor, provide facile and fast deposition on the target substrates via simple spin-casting technique. The newly developed NFGM devices exhibit superb mechanical/electrical stability against pure bending and repeated program/erase (P/E) operations without additional tunneling dielectric layer which enhances data retention capacity and helps the charge carriers to be trapped in the NPs. Furthermore, size effect of CoFe2O4 NPs (5, 8, and 11 nm) on electrical memory performance in NFGM devices was investigated.