Natural biomaterial-based memristor bearing protonated polydopamine with enhanced bipolar resistive switching performance and environmental robustness

Abstract

The searching for green memristor with good environmental robustness will be significant for next generation biodegradable devices. In this work, bio-compatible and non-toxic polydopamine (PDA) was prepared by self-polymerization of dopamine in simple aqueous solution, which was protonated by different acid concentrations (3–12 M HCl) and further fabricated as memory devices with structures of FTO/PDA/Ag. The ON/OFF ratio are enhanced gradually from 2.80 × 102 (PDA-3 M), 8.39 × 102 (PDA-6 M), 5.18 × 103 (PDA-9 M) to 2.41 × 104 (PDA-12 M). The lower conjugated degree, the closer lattice packing and the less radicals after acid treatment are the reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor. The resistive switching mechanism is the conductive filament with three processes of Ohm, space charge limited conduction (SCLC) and trap-filled limited (TFL). In addition, the FTO/PDA-12 M/Ag exhibit good environmental robustness, including thermal (100 °C) and ionizing irradiation (UV exposure for 96 h). In all, the facial protonation treatment and the simple sandwich device structures together with good environmental robustness endow its promising applications in as green, stable and biodegradable next generation electron devices.