Significance of polymer matrix on the resistive switching performance of lead-free double perovskite nanocomposite based flexible memory device

Abstract

Polymer based resistive switching (RS) is one of the most rapidly growing memory technology that is being developed for next-generation flexible/wearable devices. In this work, we have chosen two types of host polymer matrix to support the Pb-free Cs2AgBiBr6 double perovskite nanofillers. Selection of poly(methyl methacrylate) (PMMA) and polyethylene oxide (PEO) is based on their nature of insulating and ionic conductivity respectively. To eliminate the dominance of electrode on (RS), Au and ITO were chosen as top and bottom electrode respectively. The PEO based device with or without nanofiller did not show significant differences in device performance. On the contrary, substantial impact of nanofiller in PMMA based devices could be observed. Interestingly, with the concentration of 2% Cs2AgBiBr6 nanofillers in both the polymer matrix, the devices exhibited adequate bipolar memory switching behavior. However, the PMMA composite device (with 2% nanofiller) exhibited excellent RS properties such as low operating voltage, high current ON/OFF ratio, long endurance and retention in both normal and bending mode. Low value of ON/OFF ratio in PEO composite device could be attributed to higher conductivity of PEO polymer matrix that result into high current in the OFF state. Finally, the indispensable results in the PMMA nanocomposite based flexible device was hypothesized by using energy band diagram on the basis of charge trapping/de-trapping inside the functional matrix and pave the way for the development of next-generation flexible electronics.