CdS nanocrystals formed in SiO2 substrates by ion implantation

In this work, CdS nanocrystals were formed in SiO2 substrates by implantation of Cd and S atoms (up to 1017/cm2) and subsequent annealing (up to 900°C). The implanted and annealed layer was studied by X-ray diffraction (XRD), UV transmittance and reflectance measurements (energy range 1.4–6.5 eV), and Raman spectroscopy. Upon annealing, all methods proved the synthesis of CdS crystallites from the starting components, and the features characteristic of the CdS-phase were strongly and consistently dependent on ion dose and annealing temperature. The analysis of the results shows that by implantation and post-implantation treatment, the average size of CdS crystallites can be controlled, and that smaller CdS nanocrystals are obtained for lower doses and lower annealing temperatures.