Dynamic Random Access Memory Effect and Memory Device Derived from a Functional Polyimide Containing Electron Donor‐Acceptor Pairs in the Main Chain

Abstract

A functional polyimide, hexafluoroisopropyl bis(phthalic dianhydride)/3,6-diaminocarbazole (6FDA/DAC), in which DAC serves as electron donor and 6FDA as electron acceptor, has been synthesized in our present work. Electrical characterization results on the sandwiched polyimide memory device (ITO/Thin polyimide Layer/Au) indicate that the polyimide possesses electrical bistability and the device exhibits two accessible conductivity states, which can be reversibly switched from the low-conductivity (OFF) state to the high-conductivity (ON) state with an ON/OFF current ratio of about 10(4). Different from the widely reported write-once-read-many-times (WORM) effects, the device with the 6FDA/DAC polyimide as the active layer shows dynamic random access memory (DRAM) behavior. The ON state of the device was lost immediately after removal of the applied voltage, while by applying a constant bias (e.g., 3 V) the ON state can be electrically sustained. The roles of donor and acceptor components in the polyimide main chain were elucidated through molecular simulation.

The synthesis and flash memory behavior of alternate copolymer containing carbazole donor and perylenediimide derivatives acceptor by the hybridization of organo-silicon

“…A number of donor-acceptor copolymers have been designed and synthesized, which could give the desired electronic properties within a single molecule for the resistor-type memory device applications. [16][17][18][19] However, most of these donor-acceptor polymers consist of the aliphatic hydrocarbon backbones, which exhibit the relative high switch-on voltages as well as low dimensional stability. It has been well established that the polyimides could be used in devices, such as static random access memory (SRAM), write-once-readmany times (WORM), dynamic random access memory (DRAM) and flash memory under an external voltage bias or pulse.…”

Electrical Bistability and Erasable Memory Effect of a Functional Polyimide Film: Synthesis and Investigation of Mechanism

“…[15][16][17][18][19][20][21][22] In our previous research, PI with WORM, DRAM, and flash memory behavior have been synthesized. [23][24][25][26] We thus believe it is possible to achieve diverse PI memory materials by selecting appropriate functional groups or by adjusting the configuration of the polymer chain to generate different types of charge-transfer and different energy gaps. The outstanding thermal and mechanical properties of PI might also enable application of these memory devices in the electronic information industry.…”

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

“…Since the first polymer electronic memory reported in 1970 by Sliva [9], many different polymers or polymer-based hybrids have been found to exhibit electrical memory switching characteristics, including conjugated polymers such as poly (9,9-bis(4-diphenylaminophenyl)-2,7-fluorene) (PDPAF) [10], vinyl polymers with specific pendent groups such as poly(N-vinylcarbazole) (PVK) [8,11,12], functional polyimides (PIs) [1,2,13], and polymer nanocomposites embedded with metal nanoparticles [14], fullerenes [15], carbon nanotubes (CNTs) [7], graphene [16], and graphene oxide (GO) [17]. Among them, aromatic polyimides (PIs) were considered to be the most promising candidate for memory applications due to their high-temperature stability, dimensional stability and outstanding mechanical properties.…”

“…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.…”