GISAXS studies of morphology and size distribution of CdS nanocrystals formed in SiO 2 by ion implantation

Abstract

Grazing incidence small angle X-ray scattering (GISAXS) was applied to study the synthesis and size evolution of CdS nanocrystals. CdS was formed in SiO 2 substrate by successive multi-energy implantation of constituent elements (three different ion doses) and subsequent thermal annealing ( T a=800 or 1000 °C). The analysis of 2D GISAXS patterns with the Guinier plot was compared to the fit results of the local mono-disperse approximation. Results indicate that the applied implantation+annealing procedure resulted in formation of isolated, spherical CdS nanoparticles embedded in SiO 2 amorphous matrix, evenly distributed in the substrate in all three dimensions. Nanoparticle average size, size distribution, inter-particle distance and fraction of synthesized atoms were determined. Larger doses induced strong clustering into larger nanoparticles, accompanied with the increase of inter-cluster distance, that indicates the strain-related enhancement of the diffusion of small CdS nanocrystals. Results promote GISAXS as an excellent and nondestructive tool to investigate the role of particular implantation and annealing steps, in term of nanocrystal size, morphology and size distribution of CdS nanocrystals.