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Efficient visible luminescence of nanocrystalline silicon prepared from amorphous silicon films by thermal annealing and stain etching.

Timoshenko VY, Gonchar KA, Mirgorodskiy IV, Maslova NE, Nikulin VE, Mussabek GK, Taurbaev YT, Svanbayev EA, Taurbaev TI - Nanoscale Res Lett (2011)

Bottom Line: In contrast to as-deposited a-Si:H films, the nc-Si films after stain etching exhibited efficient photoluminescence in the spectral range of 600 to 950 nm at room temperature.The photoluminescence intensity and lifetimes of the stain etched nc-Si films were similar to those for conventional porous Si formed by electrochemical etching.The obtained results indicate new possibilities to prepare luminescent thin films for Si-based optoelectronics.

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Affiliation: Department of Physics, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia. timoshen@phys.msu.ru.

ABSTRACT
Films of nanocrystalline silicon (nc-Si) were prepared from hydrogenated amorphous silicon (a-Si:H) by using rapid thermal annealing. The formed nc-Si films were subjected to stain etching in hydrofluoric acid solutions in order to passivate surfaces of nc-Si. The optical reflectance spectroscopy revealed the nc-Si formation as well as the high optical quality of the formed films. The Raman scattering spectroscopy was used to estimate the mean size and volume fraction of nc-Si in the annealed films, which were about 4 to 8 nm and 44 to 90%, respectively, depending on the annealing regime. In contrast to as-deposited a-Si:H films, the nc-Si films after stain etching exhibited efficient photoluminescence in the spectral range of 600 to 950 nm at room temperature. The photoluminescence intensity and lifetimes of the stain etched nc-Si films were similar to those for conventional porous Si formed by electrochemical etching. The obtained results indicate new possibilities to prepare luminescent thin films for Si-based optoelectronics.

No MeSH data available.


Photoluminescence spectra of a-Si:H film and samples #1 (triangles), #2 (squares), and #3 (solid line) after SE. The spectrum of porous Si prepared by electrochemical etching (anodization) is also shown for comparison.
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Figure 3: Photoluminescence spectra of a-Si:H film and samples #1 (triangles), #2 (squares), and #3 (solid line) after SE. The spectrum of porous Si prepared by electrochemical etching (anodization) is also shown for comparison.

Mentions: The PL measurements did not reveal any remarkable light emission for as-prepared a-Si:H films as well as for the RTA-treated ones without the SE procedure. The efficient PL in the spectral range of 600 to 950 nm was observed for the thermally annealed films after the SE treatment (see Figure 3). The intensity, spectral position and lifetime of PL were similar to those measured for porous Si formed from c-Si by SE in the same solution or by standard anodization in HF-based electrolyte [2]. The observed PL of the nc-Si films after SE can be attributed to the radiative recombination of excitons confined in passivated nc-Si [9,10]. Since no PL was observed from the films of a-Si:H after SE the formation of nc-Si seems to be necessary for the efficient PL.


Efficient visible luminescence of nanocrystalline silicon prepared from amorphous silicon films by thermal annealing and stain etching.

Timoshenko VY, Gonchar KA, Mirgorodskiy IV, Maslova NE, Nikulin VE, Mussabek GK, Taurbaev YT, Svanbayev EA, Taurbaev TI - Nanoscale Res Lett (2011)

Photoluminescence spectra of a-Si:H film and samples #1 (triangles), #2 (squares), and #3 (solid line) after SE. The spectrum of porous Si prepared by electrochemical etching (anodization) is also shown for comparison.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211438&req=5

Figure 3: Photoluminescence spectra of a-Si:H film and samples #1 (triangles), #2 (squares), and #3 (solid line) after SE. The spectrum of porous Si prepared by electrochemical etching (anodization) is also shown for comparison.
Mentions: The PL measurements did not reveal any remarkable light emission for as-prepared a-Si:H films as well as for the RTA-treated ones without the SE procedure. The efficient PL in the spectral range of 600 to 950 nm was observed for the thermally annealed films after the SE treatment (see Figure 3). The intensity, spectral position and lifetime of PL were similar to those measured for porous Si formed from c-Si by SE in the same solution or by standard anodization in HF-based electrolyte [2]. The observed PL of the nc-Si films after SE can be attributed to the radiative recombination of excitons confined in passivated nc-Si [9,10]. Since no PL was observed from the films of a-Si:H after SE the formation of nc-Si seems to be necessary for the efficient PL.

Bottom Line: In contrast to as-deposited a-Si:H films, the nc-Si films after stain etching exhibited efficient photoluminescence in the spectral range of 600 to 950 nm at room temperature.The photoluminescence intensity and lifetimes of the stain etched nc-Si films were similar to those for conventional porous Si formed by electrochemical etching.The obtained results indicate new possibilities to prepare luminescent thin films for Si-based optoelectronics.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia. timoshen@phys.msu.ru.

ABSTRACT
Films of nanocrystalline silicon (nc-Si) were prepared from hydrogenated amorphous silicon (a-Si:H) by using rapid thermal annealing. The formed nc-Si films were subjected to stain etching in hydrofluoric acid solutions in order to passivate surfaces of nc-Si. The optical reflectance spectroscopy revealed the nc-Si formation as well as the high optical quality of the formed films. The Raman scattering spectroscopy was used to estimate the mean size and volume fraction of nc-Si in the annealed films, which were about 4 to 8 nm and 44 to 90%, respectively, depending on the annealing regime. In contrast to as-deposited a-Si:H films, the nc-Si films after stain etching exhibited efficient photoluminescence in the spectral range of 600 to 950 nm at room temperature. The photoluminescence intensity and lifetimes of the stain etched nc-Si films were similar to those for conventional porous Si formed by electrochemical etching. The obtained results indicate new possibilities to prepare luminescent thin films for Si-based optoelectronics.

No MeSH data available.