Structural and compositional study of Erbium-doped silicon nanocrystals by HAADF, EELS and HRTEM techniques in an aberration corrected STEM

Er-doped SiO₂ and Si nano-crystals (NCs) embedded in a SiO ₂ matrix were produced by ion beam implantation of Si (100) substrates. After annealing Er ions agglomerate in different positions with different compositional properties in samples with and without Si implants. HAADF and EELS show that in the sample with Si implants the Si and Er distribution is identical and within a band of ∼110nm width ∼75nm below theSiO₂ surface whereas in the sample with no excess Si, Er forms on average much larger, amorphous aggregates, presumably an Er-oxide, in the SiO₂ matrix with tendency to move towards the surface of the SiO ₂ layer.