Germanium antimony quantum dots morphology and Raman spectroscopy fabricated by inert gas condensation

Abstract

Phase change materials (PCM) based on nanostructure are attractive interest for non-volatile memory due to their high data–storage density and low power consumption. Germanium antimony (Ge-Sb) quantum dots (QDs) with tunable size and density have been fabricated on mica, silicon, and quartz glass substrates by magnetron sputtering with inert gas condensation. The deposition time rate plays an important role in the formation of the monodisperse or aggregate quantum dots. The dots’ morphology, in terms of size and density as observed by atomic force microscopy (AFM) strongly depends on the deposition time rate. The size of QDs was observed by (AFM) images topography between 1.6 and 3.2 nm. Raman spectroscopy measurements reveal that Ge-Sb phonon at 250 cm−1 (Lo mode) and 220 cm−1 (To mode). Also, strong Sb-Sb crystallized peaks positioned at about 145 cm−1 and 110 cm−1 is observed. Keywords: Ge-Sb quantum dots, Atomic force microscopy, Magnetron sputtering, Raman spectroscopy