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

초록

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 degrees 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 (approximate to 294 times at 70 degrees C and approximate to 42 times at 110 degrees C) by adding only 2 mol% PAMPSA to the PVA films and further improved at 10 mol% PAMPSA (>11.7 cm(2) V(-1)s(-1) at 70 degrees C and >3.8 cm(2) V-1 s(-1) at 110 degrees C). The hysteresis characteristics are rather strengthened for the PVA:PAMPSA layers by annealing at 110 degrees 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 degrees C. The optimized OFETs with the PVA:PAMPSA layers (10 mol%, 110 degrees C) deliver excellent data retention characteristics during >10 000 memory cycles at a voltage range of -5 to +5 V.

키워드