Nonvolatile write-once read-many-times memory device based on an aromatic hyperbranched polyimide bearing triphenylamine moieties

Abstract

An aromatic hyperbranched polyimide, poly(N,N,N′,N′-tetrakis(4-aminophenyl)benzidine-N,N- 4,4′-hexafluoroisopropylidene-diphthalimide) (6F-TEAPBD PI), was synthesized. Semiconductor parameter analysis on the sandwich devices using the synthesized polyimide as the active layer indicates that the polymer possesses distinct electrical bi-stable states with an ON/OFF current ratio of about 300 and a switching voltage at around 2.0 V, which could be applied as nonvolatile write-once read-many-times (WORM) memory. Mechanisms associated with the electrical switching effect are discussed on the basis of the experimental and quantum simulation results. It is suggested that the electric-field-induced charge transport from triphenylamine moieties to hexafluoropropylidene phthalimide units and the subsequent formation of charge-transfer complexes are responsible for the observed electrical memory effect.