Memristors based on ZIF-8@Gr composite thin films: memory characterization, empirical modeling and application of secure encryption circuits

Memristors exhibit great potential in applications of neural networks, memory storage, and logic circuits. Hybrid materials based on metal-organic frameworks (MOFs) has emerged as one of the promising active materials used in memristors. In this study, zeolitic imidazolate framework-8 (ZIF-8), a typical MOF material with high porosity, was combined with graphene to form a composite material, denoted as ZIF-8@Gr. On the fluorine-doped tin oxide (FTO) coated glasses, memristors with a structure of Ag/ZIF-8@Gr/FTO were fabricated. The resistive switching memory characteristic of the devices was investigated, revealing good memory performance including a memory window of ∼10 3 , retention of 10 4 s and switching stability for 100 cycles. A universal empirical model was developed to simulate the resistance switching behaviors, resulting in a good match between simulation results and experimental data. The empirical model does not only bridge the differences in device characteristics and compensate for the performance defects of existing models, but also helps to promote the transformation of memristors from theoretical research to practical applications. Additionally, an optimized window function was applied to the typical memristor model proposed by the Hewlett Packard laboratory, enabling the construction of universal logic circuits based on memristors. Based on the developed model, a memristor-based secure encryption circuit system capable of encrypting and decrypting a range of digital data and images was designed and implemented.