Characterization of Materials UsingHard X-RAY PhotoelectronSpectroscopy (HAXPES) : Stoichiometric Analysis of Ag2 S Thin Films for NeuromorphicMemristor Applications

This project aims to analyze, both numerically and theoretically, the properties of silver sulfide (Ag2 S)thin films for potential use in memristor-based neuromorphic computing. Thin films were fabricatedusing reactive sputtering under varying hydrogen sulfide (H2 S) flow conditions, with and withoutsubstrate heating. The chemical composition of silver and sulfur was analyzed using hard X-RAYphotoelectron spectroscopy (HAXPES) and the stoichiometric ratios were quantified by fitting Voigtprofiles to the Ag 3d and S 2p peaks. Numerical integration using Simpson’s method was employed tocompute the total elemental intensity of the silver 3d and sulfur 2p spectra. Results indicate that H2 Sflow rates above 15 standard cubic centimeters/minute (sccm which is a unit of gas flow rate) promotestoichiometries closer to 2:1 Ag:S ratio. However, significant sulfur contamination from previoussputtering runs was detected at low flow rates, complicating reproducibility and interpretation. Thefindings partially support the potential of Ag2 S-based films for memristors but underscore the needfor improved chamber conditioning in future studies.