Synthesis and laser annealing of embedded CdSe-nanoparticles in SiO₂ by pulsed excimer laser radiation

CdSe-semiconductor nanocrystals embedded in SiO₂ on silicon have been synthesized by ion implantation of Cd⁺ and Se⁺ followed by pulsed excimer laser annealing at room temperature. Transmission electron microscopy and x-ray diffraction-analysis results suggest that wurzite-type embedded CdSe nanocrystals have been formed. Since laser annealing can be applied locally this opens a route towards spatially selective annealing. In a second type of experiment pulsed laser annealing was performed on embedded CdSe nanoparticles synthesized by standard thermal annealing resulting in oriented ellipsoidal deformation and morphological changes of the larger precipitates. Computer simulation results suggest a size-selective temperature increase of the CdSe nanocrystals as the underlying mechanism.