Resistive Switching Behavior in Gelatin Thin Films for Nonvolatile Memory Application

This paper presents the characteristics of gelatin, which can cause reproducible resistive switching and bipolar resistive switching in aluminum (Al)/gelatin (35 nm)/ITO devices. The memory devices exhibited a high ON/OFF ratio of over 10(6) and a long retention time of over 10(5) seconds. The resistive switching mechanism was investigated using the high-angle dark field transmission electron microscopy image of Al/gelatin/ITO devices in the pristine high-resistance state (HRS) and then in returning to HRS after the RESET process. The energy-dispersive X-ray spectroscopy analysis revealed the aggregation of N and Al elements and the simultaneous presence of carbon and oxygen elements in the rupture of filament paths. Furthermore, via a current-sensing atomic force microscopy, we found that conduction paths in the ON-state are distributed in a highly localized area, which is associated with a carbon-rich filamentary switching mechanism. These results support that the chelation of N binding with Al ions improves the conductivity of the low-resistance state but not the production of metal filaments.