Impact of buffer layer thickness on the performance of metal halide perovskite memristors

Perovskite-based memristors have emerged as promising devices for information storage and processing due to their resistive switching properties. In this study, nonvolatile resistive switching memory devices based on metal halide perovskite with structure FTO/methylammonium lead iodide (MAPbI 3 )/polymethyl methacrylate (PMMA)/Ag are presented. The influence of buffer layer thickness (PMMA) variations at 30 nm, 50 nm, and 70 nm on device performance is evaluated. Experimental results show that key device parameters such as SET voltage, ON/OFF ratio, endurance and retention time are significantly affected by changes in the buffer layer thickness. Our findings show that an optimum thickness of 50 nm improves the stability and performance of the device, with ultra-high ON/OFF ratios (10 6 ), record endurances (>3·10 4 cycles) and a record retention time (>5·10 5 s). AC characterization has also been carried out to gain a deeper understanding of the physical mechanisms governing the device. Finally, numerical simulations are carried out to understand the role of the electric field in the formation and rupture of conductive filaments within both the perovskite and buffer layers in devices with different buffer layer thicknesses. • 50 nm PMMA buffer layer yields high ON/OFF ratio (10 6 ), long retention time (>5·10 5 s) and high endurance (>3·10 4 cycles). • Ag + cation migration and electric field distribution identified as key factors governing resistive switching stability. • Experiments and numerical simulations establish a physical model for buffer thickness–dependent memristive behavior.