Low-Voltage Organic Nonvolatile Memory Transistors with Water-Soluble Polymers Containing Thermally Induced Radical Dipoles

Water-Soluble Reactive Polymer Blends for Stable Memory Layers in Low-Voltage Nonvolatile Organic Memory Transistors with High Mobility and Data-Retention Characteristics

Here we demonstrate low-voltage nonvolatile organic memory transistors, featuring high charge-carrier mobility and outstanding data-retention characteristics, by employing water-soluble reactive polymer blends as a gate-insulating memory layer. Blend films of poly(vinyl alcohol) (PVA) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) (PVA:PAMPSA) were prepared from their aqueous solutions with various molar ratios of PAMPSA (0∼18 mol%) and thermally annealed at 70 ℃ and 110 ℃. Organic field-effect transistors (OFETs) were fabricated by depositing poly(3-hexylthiophene) (P3HT) channel layers on the thermally-treated PVA:PAMPSA films. Results showed that the hole mobility of OFETs was remarkably increased (ca. 294 times at 70 ℃ and ca. 42 times at 110 ℃) by adding only 2 mol% PAMPSA to the PVA films and further improved at 10 mol% PAMPSA (>11.7 cm2/Vs at 70 ℃ and >3.8 cm2/Vs at 110 ℃). The hysteresis characteristics were rather strengthened for the PVA:PAMPSA layers by annealing at 110 ℃ due to the formation of cross-linking sites, even though the OFETs with the pristine PVA layers did almost lose hysteresis characteristics at 110 ℃. The optimized OFETs with the PVA:PAMPSA layers (10 mol%, 110 ℃) delivered excellent data retention characteristics during >10,000 memory cycles at a voltage range of -5 ∼ +5 V. This article is protected by copyright. All rights reserved.