Clima, SergiuSergiuClimaDucry, FabianFabianDucryGarbin, DanieleDanieleGarbinRavsher, TarasTarasRavsherDegraeve, RobinRobinDegraeveBelmonte, AttilioAttilioBelmonteKar, Gouri SankarGouri SankarKarPourtois, GeoffreyGeoffreyPourtois2026-04-212026-04-2120242380-9248https://imec-publications.be/handle/20.500.12860/59140The recent attention to Ovonic threshold switching (OTS) materials is owed to the development of the so-called selector-only memory (SOM) concept. Understanding the SOM switching mechanism at the atomic scale is required to facilitate device optimization. With first-principles simulations, we identify two possible atomistic mechanisms leading to mobility gap changes and hence threshold voltage modulation, which determines the memory window (MW) of SOM: i) local atomic bond rearrangement or ii) atomic segregation, depending on the operating conditions. Our findings provide an atomic-level perspective that confirms previous high-level modelling assertions about the working principles of OTS and SOM.engProceedings paper10.1109/iedm50854.2024.10873555WOS:001692734400237