Thermal degradation threshold in Ag@chondroitin sulfate memristors revealed by temperature-resolved raman spectroscopy

Abstract

Organic memristors (OMEMRs) based on biopolymeric matrices functionalized with silver nanoparticles (AgNPs) are emerging as promising candidates for next-generation non-volatile memory technologies, owing to their multilevel resistive switching behavior, scalability, and compatibility with solution-processable fabrication methods. In this study, AgNPs were coordinated with chondroitin sulfate (ChS) to produce Ag@ChS-based OMEMRs, which were fabricated via spin-coating and subjected to a comprehensive thermal stability assessment using temperature-resolved Raman spectroscopy over the 25°C–275°C range. The Raman spectra revealed a prominent vibrational mode at 76 cm−1, attributed to AgNP lattice dynamics, along with a distinct Ag–O stretching feature near 240 cm−1, indicative of coordination with carboxylate groups within the ChS matrix. A marked attenuation of sulfate-associated Raman bands was observed at approximately 175°C, signifying a critical degradation threshold associated with desulfation, interfacial breakdown, and irreversible loss of memristive functionality. These findings demonstrate that Raman spectroscopy provides a sensitive, non-destructive platform for probing thermally induced molecular transformations and diagnosing early-stage failure in biopolymer-based memristive systems. The insights gained herein offer valuable guidance for the rational design of thermally robust organic memory devices.