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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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XRD patterns of the highest and lowest Nd-doped samples annealed at 1100 °C.
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Figure 4: XRD patterns of the highest and lowest Nd-doped samples annealed at 1100 °C.

Mentions: In Figure 4 is depicted the XRD spectra of the lowest and highest Nd-doped samples. In the former sample, one broad band corresponding to a-SiO2 is observed, while the pattern of the latter sample indicates the presence of additional phases. In the 27-32° range, it shows various sharp peaks that are located above a broad band centered at 29°. This peak, and the 48° one, indicate the presence of nanocrystalline Si [21,25], while the sharp and intense peaks located at 27.6°, 28.8°, and 30.7° are assigned to Nd2O3 crystals. However, the 28.8° peak may result from both crystalline Si and Nd2O3. It is interesting to note that the 27.6° and 30.7° peaks fairly concur with the ones observed in neodymia-silica composites containing Nd2O3 nanocrystals by several groups [2,3]. As a consequence, the presence of Nd2O3 and Si nanocrystals in the highest Nd-doped sample is established, while no crystalline phases are detected in the low Nd-doped one.


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)

XRD patterns of the highest and lowest Nd-doped samples annealed at 1100 °C.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: XRD patterns of the highest and lowest Nd-doped samples annealed at 1100 °C.
Mentions: In Figure 4 is depicted the XRD spectra of the lowest and highest Nd-doped samples. In the former sample, one broad band corresponding to a-SiO2 is observed, while the pattern of the latter sample indicates the presence of additional phases. In the 27-32° range, it shows various sharp peaks that are located above a broad band centered at 29°. This peak, and the 48° one, indicate the presence of nanocrystalline Si [21,25], while the sharp and intense peaks located at 27.6°, 28.8°, and 30.7° are assigned to Nd2O3 crystals. However, the 28.8° peak may result from both crystalline Si and Nd2O3. It is interesting to note that the 27.6° and 30.7° peaks fairly concur with the ones observed in neodymia-silica composites containing Nd2O3 nanocrystals by several groups [2,3]. As a consequence, the presence of Nd2O3 and Si nanocrystals in the highest Nd-doped sample is established, while no crystalline phases are detected in the low Nd-doped one.

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