Effects of As2S3 incorporation on the structural, optical and electrical properties of Ge2Sb2Te5 films for phase change memory

This work explores the effects of As 2 S 3 doping on the structural, thermal, and electrical properties of Ge 2 Sb 2 Te 5 (GST) thin films, aiming to enhance their suitability for phase change memory (PCM) applications. A series of As 2 S 3 -doped GST compositions are synthesized and analyzed using XRD, Raman spectroscopy, VIS-NIR spectroscopy, thermal and electrical measurements. The results indicate that As 2 S 3 incorporation effectively suppresses crystallization, enhances amorphous phase stability, and improves thermal endurance. The 10-year data retention temperature increased from 78 °C (GST) to 106.7 °C at 21 at.% of As 2 S 3 . Electrical switching measurements showed a decrease in threshold current. Furthermore, COMSOL Multiphysics simulations revealed enhanced thermal confinement and more localized heating in the doped films, which directly influence power consumption. These findings suggest that As 2 S 3 -doped GST offers a promising direction toward high-performance and thermally stable PCM devices. • As 2 S 3 doping drives phase change from amorphous to FCC, then to stable HEX structure. • Sheet resistance increases with dopant concentration of As 2 S 3 . • Elevated crystallization temperature in As 2 S 3 -doped films enhances thermal stability. • Higher activation energy after addition of As 2 S 3 improves long-term data retention. • Bandgap widens due to stronger carrier localization after doping. • Reduced threshold current with higher threshold voltage enables power-efficient switching. • Finite element results show the improvement in Joule heating efficiency.