Dislocations in Si nanocrystals embedded in SiO2.

Si nanocrystals (Si nc) were formed by the implantation of Si(+) into a SiO2 film on (100) Si, followed by high-temperature annealing. High-resolution transmission electron microscopy has been used to investigate the dislocations in the Si nc produced by a high-dose (ion fluence of 3 x 10(17) cm(-2)) implantation. Three different kinds of dislocations, namely perfect, extended and mismatch dislocations, have been observed in some Si nc. The possible formation mechanism for these dislocations has been discussed. The dislocations in the Si nc are expected to have a great influence on the photoluminescence from Si nc embedded in SiO2.