[Effect of Ce3+ implantation on photoluminescence intensity of Si nanocrystals embedded in superlattices].

ABSTRACT

In the present paper, SiO/SiO2 superlattices samples were prepared on Si substrates by electron beam evaporation. The samples were annealed in nitrogen atmosphere at high temperature subsequently. And then, Ce3+ ions with a dose of 2.0 x 10(14) and 2.0 x 10(15) cm(-2) respectively were implanted into these samples with formed Si nanocrystals. The photoluminescence (PL) spectra showed that the PL intensities of samples with Ce3+ implanting dropped sharply compared with the samples without Ce3+ implanting. The PL intensity increased gradually with increasing re-annealing temperature, but dropped again when the temperature exceeded 600 degrees C. The PL intensity even could be higher than that of samples without Ce3+ implanting if only the dose of Ce3+ was 2.0 x 10(14) cm(-2). When the dose of Ce3+ was 2.0 x 10(15) cm(-2), the PL intensity couldn't exceed that of samples without Ce3+ implanting even when the re-annealing temperature was 600 degrees C. Further investigations showed that the varieties of the PL intensities were mainly dependent on the re-annealing temperature, which had the best point at 600 degrees C, and the dose of Ce3+ had the right value. Furthermore, the experiment results proved that there was energy transfer from Ce3+ to Si nanocrystals in this kind of structure.