The effect of irradiation with He+, F+ and P+ ions with various energies upon photoluminescence and structure of Si nanocrystals was studied. It was established that, at low intensities of ion losses, quenching of photoluminescence was provided by individual atomic displacements. However, as the intensity was increased, quenching was accompanied by an increase in nuclear losses. It was believed that, in low-density displacement cascades, mobile defects predominantly drained to the surface, where they formed the centers of non-radiative recombination. In contrast, mobile defects partially formed stable structural defects within the nanocrystals in dense cascades. This was sufficient to accumulate ∼0.06dpa for the amorphization of Si nanocrystals at 20C; a dependence of this effect upon the intensity of the ion energy loss was not observed. It was also noted that there was a low probability of annihilation of vacancies and interstitials within Si nanocrystals. This effect was attributed to the presence of an energy barrier.

Effect of the Ion-Energy Loss Rate on Defect Formation during Implantation in Silicon Nanocrystals. G.A.Kachurin, S.G.Cherkova, D.V.Marin, A.K.Gutakovskiĭ, A.G.Cherkov, V.A.Volodin: Semiconductors, 2008, 42[9], 1127-31