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

Abstract

Here 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 are demonstrated. Blend films of poly(vinyl alcohol) (PVA) and poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPSA) (PVA:PAMPSA) are prepared from their aqueous solutions with various molar ratios of PAMPSA (0–18 mol%) and thermally annealed at 70 and 110 °C. Organic field‐effect transistors (OFETs) are fabricated by depositing poly(3‐hexylthiophene) (P3HT) channel layers on the thermally treated PVA:PAMPSA films. Results show that the hole mobility of OFETs is remarkably increased (≈294 times at 70 °C and ≈42 times at 110 °C) by adding only 2 mol% PAMPSA to the PVA films and further improved at 10 mol% PAMPSA (>11.7 cm2 V−1s−1 at 70 °C and >3.8 cm2 V−1 s−1 at 110 °C). The hysteresis characteristics are rather strengthened for the PVA:PAMPSA layers by annealing at 110 °C due to the formation of cross‐linking sites, even though the OFETs with the pristine PVA layers do almost lose hysteresis characteristics at 110 °C. The optimized OFETs with the PVA:PAMPSA layers (10 mol%, 110 °C) deliver excellent data retention characteristics during >10 000 memory cycles at a voltage range of −5 to +5 V.