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Effect of the Nd content on the structural and photoluminescence properties of silicon-rich silicon dioxide thin films.

Debieu O, Cardin J, Portier X, Gourbilleau F - Nanoscale Res Lett (2011)

Bottom Line: Under non-resonant excitation at 488 nm, our Nd-doped SRSO films simultaneously exhibited PL from Si-np and Nd3+ demonstrating the efficient energy transfer between Si-np and Nd3+ and the sensitizing effect of Si-np.Moreover, the presence of Nd-oxide nanocrystals in the highest Nd-doped sample was established by XRD.It is, therefore, suggested that the Nd clustering, as well as disorder, are responsible for the concentration quenching of the PL of Nd3+.

View Article: PubMed Central - HTML - PubMed

Affiliation: CIMAP, UMR CNRS/CEA/ENSICAEN/UCBN, Ensicaen 6 Bd Maréchal Juin, 14050 Caen Cedex 4, France. fabrice.gourbilleau@ensicaen.fr.

ABSTRACT
In this article, the microstructure and photoluminescence (PL) properties of Nd-doped silicon-rich silicon oxide (SRSO) are reported as a function of the annealing temperature and the Nd concentration. The thin films, which were grown on Si substrates by reactive magnetron co-sputtering, contain the same Si excess as determined by Rutherford backscattering spectrometry. Fourier transform infrared (FTIR) spectra show that a phase separation occurs during the annealing because of the condensation of the Si excess resulting in the formation of silicon nanoparticles (Si-np) as detected by high-resolution transmission electron microscopy and X-ray diffraction (XRD) measurements. Under non-resonant excitation at 488 nm, our Nd-doped SRSO films simultaneously exhibited PL from Si-np and Nd3+ demonstrating the efficient energy transfer between Si-np and Nd3+ and the sensitizing effect of Si-np. Upon increasing the Nd concentration from 0.08 to 4.9 at.%, our samples revealed a progressive quenching of the Nd3+ PL which can be correlated with the concomitant increase of disorder within the host matrix as shown by FTIR experiments. Moreover, the presence of Nd-oxide nanocrystals in the highest Nd-doped sample was established by XRD. It is, therefore, suggested that the Nd clustering, as well as disorder, are responsible for the concentration quenching of the PL of Nd3+.

No MeSH data available.


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Evolution of the PL spectra as a function of the Nd concentration.
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Figure 7: Evolution of the PL spectra as a function of the Nd concentration.

Mentions: Figure 7 shows the behavior of the PL spectra of the thin films annealed at 1100 °C as a function of the Nd concentration. As the Nd content increases from 0.08 to 0.27 at.%, the PL intensity of Si-np drastically drops and disappears at 1.68 at.%. Then, PL of Si-np surprisingly reappears at the highest Nd concentration of 4.9 at.%. Interestingly, one can observe that the positions and widths of the PL peaks of the two lowest Nd-doped samples remain identical (see the inset); whereas the PL peak of the highest Nd-doped film is manifestly shifted to longer wavelengths. According to the quantum confinement model, the PL of the latter sample therefore emanates from Si-np that are sensibly larger than the ones present in the two former samples. In the infrared spectral domain, one can observe that the PL intensity of Nd3+ ions drops progressively with increasing Nd concentration.


Effect of the Nd content on the structural and photoluminescence properties of silicon-rich silicon dioxide thin films.

Debieu O, Cardin J, Portier X, Gourbilleau F - Nanoscale Res Lett (2011)

Evolution of the PL spectra as a function of the Nd concentration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211213&req=5

Figure 7: Evolution of the PL spectra as a function of the Nd concentration.
Mentions: Figure 7 shows the behavior of the PL spectra of the thin films annealed at 1100 °C as a function of the Nd concentration. As the Nd content increases from 0.08 to 0.27 at.%, the PL intensity of Si-np drastically drops and disappears at 1.68 at.%. Then, PL of Si-np surprisingly reappears at the highest Nd concentration of 4.9 at.%. Interestingly, one can observe that the positions and widths of the PL peaks of the two lowest Nd-doped samples remain identical (see the inset); whereas the PL peak of the highest Nd-doped film is manifestly shifted to longer wavelengths. According to the quantum confinement model, the PL of the latter sample therefore emanates from Si-np that are sensibly larger than the ones present in the two former samples. In the infrared spectral domain, one can observe that the PL intensity of Nd3+ ions drops progressively with increasing Nd concentration.

Bottom Line: Under non-resonant excitation at 488 nm, our Nd-doped SRSO films simultaneously exhibited PL from Si-np and Nd3+ demonstrating the efficient energy transfer between Si-np and Nd3+ and the sensitizing effect of Si-np.Moreover, the presence of Nd-oxide nanocrystals in the highest Nd-doped sample was established by XRD.It is, therefore, suggested that the Nd clustering, as well as disorder, are responsible for the concentration quenching of the PL of Nd3+.

View Article: PubMed Central - HTML - PubMed

Affiliation: CIMAP, UMR CNRS/CEA/ENSICAEN/UCBN, Ensicaen 6 Bd Maréchal Juin, 14050 Caen Cedex 4, France. fabrice.gourbilleau@ensicaen.fr.

ABSTRACT
In this article, the microstructure and photoluminescence (PL) properties of Nd-doped silicon-rich silicon oxide (SRSO) are reported as a function of the annealing temperature and the Nd concentration. The thin films, which were grown on Si substrates by reactive magnetron co-sputtering, contain the same Si excess as determined by Rutherford backscattering spectrometry. Fourier transform infrared (FTIR) spectra show that a phase separation occurs during the annealing because of the condensation of the Si excess resulting in the formation of silicon nanoparticles (Si-np) as detected by high-resolution transmission electron microscopy and X-ray diffraction (XRD) measurements. Under non-resonant excitation at 488 nm, our Nd-doped SRSO films simultaneously exhibited PL from Si-np and Nd3+ demonstrating the efficient energy transfer between Si-np and Nd3+ and the sensitizing effect of Si-np. Upon increasing the Nd concentration from 0.08 to 4.9 at.%, our samples revealed a progressive quenching of the Nd3+ PL which can be correlated with the concomitant increase of disorder within the host matrix as shown by FTIR experiments. Moreover, the presence of Nd-oxide nanocrystals in the highest Nd-doped sample was established by XRD. It is, therefore, suggested that the Nd clustering, as well as disorder, are responsible for the concentration quenching of the PL of Nd3+.

No MeSH data available.


Related in: MedlinePlus