Organic One-Transistor-Type Nonvolatile Memory Gated with Thin Ionic Liquid-Polymer Film for Low Voltage Operation

Abstract

As one of the most emerging next-generation nonvolatile memories, one-transistor (1T)-type nonvolatile memories are of great attention due to their excellent memory performance and simple device architecture suitable for high density memory arrays. In particular, organic 1T-type memories containing both organic semiconductors and insulators are further beneficial because of their mechanical flexibility with low cost fabrication. Here, we demonstrate a new flexible organic 1T-type memory operating at low voltage. The low voltage operation of a memory less than 10 V was obtained by employing a polymer gate insulator solution blended with ionic liquid as a charge storage layer. Ionic liquid homogeneously dissolved in a thin poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) film gave rise to low voltage operation of a device due to its high capacitance. Simultaneously, stable charge trapping of either anions or cations efficiently occurred in the polymer matrix, dependent upon gate bias. Optimization of ionic liquid in PVDF-TrFE thus led to an air-stable and mechanically flexible organic 1T-type nonvolatile memory operating at programming voltage of ±7 V with large ON/OFF current margin of approximately 10(3), reliable time-dependent data retention of more than 10(4) seconds, and write/read endurance cycles of 80.

Enhanced stability of the HfO2 electrolyte and reduced working voltage of a CB-RAM by an ionic liquid

“…23 At present, the mechanism of how the IL improved stability of electrolytes or water molecules inside the HfO 2 pore is still unclear. Not only low voltage operation but also high robustness against voltage stress have thus been accomplished.…”

Recent Advances of Flexible Data Storage Devices Based on Organic Nanoscaled Materials

“…The memory window was ≈7 V and almost no considerable changes were found under a large bend radius (1 mm). Another low‐voltage one‐transistor‐type memory device with P3HT as semiconductor material and adopted a P(VDF‐TrFE) solution blended with ionic liquid‐polymer as charge storage materials was reported by Hwang et al As it is shown in Figure , the operation voltage is less than 10 V due to the high capacitance of the ionic liquid‐polymer composite films which airing from the electrical double layers at the electrodes– ionic liquids interface. The anions and cations can be efficiently trapped in the polymer matrix.…”

Thin-film organic semiconductor devices: from flexibility to ultraflexibility

“…High performance flexible OMDs, including organic resistors [195][196][197][198][199][200], OFET memories [16,39,[201][202][203][204][205][206][207][208] and other complex-structured memories [209,210], are vastly investigated concerning high switching speed, high on/off ratios, long retention time, and even multi-level states or multi-functionalities [211]. They show tremendous applications in sensor arrays [212][213][214], braille displays [39], integrated circuits [215] and RFIDs [48].…”