Biodegradable transient resistive random-access memory based on MoO3/MgO/MoO3 stack

High-performance biodegradable transient resistive random-access memories (RRAMs) with the structure of Mg/MoO3/MgO/MoO3/Mg have been fabricated on a polylactic acid (PLA) substrate. Without the electroforming process, the devices have high ratios of the high-resistance state (HRS)/low-resistance state (LRS) (>50% of devices reaching above 10(6) and similar to 3% reaching above 10(11)), good retention properties (both the HRS and LRS without deterioration within 2 x 10(4) s), and good endurance properties (continuously switched between the HRS and LRS >100 times under appropriate voltage pulses). By investigating the effect of different top electrode (TE) and bottom electrode (BE) combinations (TE/BE: Mg/Mg, Pt/Mg, Mg/Pt, and Mg/Au) and different oxygen contents of MoO3 on the performance of devices, the resistive switching mechanism is revealed to be the redox of the Mg TE at the interface of Mg/MoO3. The HRS is attributed to the formation of MgO after Mg is oxidized by mobile oxygen ions or oxygen captured from adjacent MoO3 under applied voltage, while the LRS is ascribed to the dissolution of formed MgO. The fitting results of the measured data indicate that the conduction of the HRS is dominated by the Poole-Frenkel (P-F) emission and that of the LRS is governed by the Ohmic conduction. Moreover, the devices can degrade quickly in 0.9% NaCl solution within 5 h, except for the PLA substrate that is able to degrade in the human body.