Bifunctional Silver-Doped ZnO for Reliable and Stable Organic-Inorganic Hybrid Perovskite Memory

Halide perovskites (HPs) have possible uses as an active layer for emerging memory devices due to their low operation voltage and high on/off ratio. However, HP-based memory devices, which are operated by the formation of a conductive filament, still suffer from reliability issues such as limited endurance and stability. To solve the problems, it is essential to control filament formation in the active layer. Here, we present nanoscale HP-based memory devices that have a Ag-doped ZnO (AZO) layer on HP. The AZO layer is used as a Ag ion reservoir for filament formation in HP, and this reservoir enables control of filament formation. By adjusting the Ag concentration in the AZO layer, the controlled filament composed of Ag can be formed; as a result, the memory device has excellent endurance (3 × 10⁴ cycles) compared to the device that uses a Ag electrode instead of an AZO layer (4 × 10² cycles). Also, an AZO layer can passivate HP, so the device operates stably in ambient air for 15 days with a high on/off ratio (10⁶). These results demonstrate that the introduction of the AZO layer can improve the reliability of HP-based memory devices for high-density applications.