Nonvolatile Electrical Switching and Write-Once Read-Many-Times Memory Effects in Functional Polyimides Containing Triphenylamine and 1,3,4-Oxadiazole Moieties

Abstract

This work reports the synthesis and characterization of a series of functional aromatic polyimides (OXTA-PI)s containing triphenylamine and 1,3,4-oxadiazole moieties. All the polyimides exhibit high glass transition temperatures of 309-319°C. A resistive switching device with the sandwich structure of indium-tin oxide/polymer/Al was fabricated using the soluble polyimide from 4,4 0 -hexafluoroisopropylidenediphthalic anhydride (OXTA-PIa). The device exhibits two conductivity states and can be switched from the initial low-conductivity (OFF) state to the high-conductivity (ON) state at the threshold voltages of 1.8 V under both positive and negative electrical sweeps, with an ON/OFF state current ratio in the order of 10 5 . The ON state of the device is nonvolatile and can withstand a constant voltage stress of -1 V for 6 h and 10 8 pulse read cycles at -1 V under ambient conditions. Upon reversing the bias, the ON state cannot be reset to the initial OFF states. The nonvolatile and inerasable nature of the ON state, as well as the ability to write, read, and sustain the electrical states, fulfills the requirements of a write-once read-many-times (WORM) memory.

Solution-processable triarylamine-based high-performance polymers for resistive switching memory devices

“…Wang et al 71 synthesized a series of functional PIs P17a-e with different phthalimide electron acceptors, which showed excellent thermal stability and high glass transition temperatures (T g ). Memory devices based on P17a thin films exhibited symmetric bistable WORM memory behaviors with switching threshold voltages of ± 1.8 V. The ON states of the devices are nonvolatile and can withstand a constant voltage stress of − 1 V for 6 h and 10 8 pulse read cycles under ambient conditions.…”

Polyimide memory: a pithy guideline for future applications

“…18,20 The D structures of AZTA-PIa and OXTA-PIa consist of TPA-substituted diphenyltriazole and TPAsubstituted phenyloxadiazole, respectively, while the A structure is set to 6FDI. 18,20 The D structures of AZTA-PIa and OXTA-PIa consist of TPA-substituted diphenyltriazole and TPAsubstituted phenyloxadiazole, respectively, while the A structure is set to 6FDI.…”

Polymer memory devices with widely tunable memory characteristics based on functional copolynaphthalimides bearing varied fluorene and triphenylamine moieties

“…And, through the condensation polymerization reactions of different multi-functional amines, which were designed to contain electron-donating moieties such as triphenylamine [4,21,22], carbazole [19,23], ferrocene [24,25], oxadiazole [26,27], pyrene [28,29] and anthracene [30], with the electron-withdrawing dianhydries (usually 6FDA), electroactive PIs with different types of memory effects including write-once-read-many-times (WORM) [31,32], re-writable (flash) memory [12,33], dynamic random access memory (DRAM) [14,19,22] and static random access memory (SRAM) [26] have been realized. A recent report by Ueda [34] has highlighted the importance of this rapidly-growing field, and reviewed the progress and continually-increasing research enthusiasm on the polyimide memory materials and devices.…”