Limits...
On the nature of the stretched exponential photoluminescence decay for silicon nanocrystals.

Zatryb G, Podhorodecki A, Misiewicz J, Cardin J, Gourbilleau F - Nanoscale Res Lett (2011)

Bottom Line: It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function.It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm.Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. artur.p.podhorodecki@pwr.wroc.pl.

ABSTRACT
The influence of hydrogen rate on optical properties of silicon nanocrystals deposited by sputtering method was studied by means of time-resolved photoluminescence spectroscopy as well as transmission and reflection measurements. It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function. It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm. Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.

No MeSH data available.


Related in: MedlinePlus

The time-resolved PL measured for samples with various rH (10%, 30% and 50%). The nonsymmetrical emission band shape is due to the cutoff of PMT detector.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211150&req=5

Figure 1: The time-resolved PL measured for samples with various rH (10%, 30% and 50%). The nonsymmetrical emission band shape is due to the cutoff of PMT detector.

Mentions: Figure 1 shows time-resolved PL spectra measured for samples with rH = 10%, 30% and 50%. In each case, the broad emission band centered at around 1.5 eV may be observed (the nonsymmetrical emission band shape is due to the cut-off of PMT detector). What is more, the PL intensity significantly drops after increasing rH from 10% to 30% and then decreases only slightly. The lack of PL shift with rH variation indicates that the observed emission rather cannot be attributed to the quantum confinement effect. It may, however, be attributed to some emission centers at the interface between Si-NCs and SiO2 matrix (surface states) because according to what has been shown [15], defect states localized on the nanocrystal surface may suppress the quantum confinement effect on the emission spectra. Similar effect has also been observed in one of our previous papers [16] for Si-NCs.


On the nature of the stretched exponential photoluminescence decay for silicon nanocrystals.

Zatryb G, Podhorodecki A, Misiewicz J, Cardin J, Gourbilleau F - Nanoscale Res Lett (2011)

The time-resolved PL measured for samples with various rH (10%, 30% and 50%). The nonsymmetrical emission band shape is due to the cutoff of PMT detector.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211150&req=5

Figure 1: The time-resolved PL measured for samples with various rH (10%, 30% and 50%). The nonsymmetrical emission band shape is due to the cutoff of PMT detector.
Mentions: Figure 1 shows time-resolved PL spectra measured for samples with rH = 10%, 30% and 50%. In each case, the broad emission band centered at around 1.5 eV may be observed (the nonsymmetrical emission band shape is due to the cut-off of PMT detector). What is more, the PL intensity significantly drops after increasing rH from 10% to 30% and then decreases only slightly. The lack of PL shift with rH variation indicates that the observed emission rather cannot be attributed to the quantum confinement effect. It may, however, be attributed to some emission centers at the interface between Si-NCs and SiO2 matrix (surface states) because according to what has been shown [15], defect states localized on the nanocrystal surface may suppress the quantum confinement effect on the emission spectra. Similar effect has also been observed in one of our previous papers [16] for Si-NCs.

Bottom Line: It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function.It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm.Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. artur.p.podhorodecki@pwr.wroc.pl.

ABSTRACT
The influence of hydrogen rate on optical properties of silicon nanocrystals deposited by sputtering method was studied by means of time-resolved photoluminescence spectroscopy as well as transmission and reflection measurements. It was found that photoluminescence decay is strongly non-single exponential and can be described by the stretched exponential function. It was also shown that effective decay rate probability density function may be recovered by means of Stehfest algorithm. Moreover, it was proposed that the observed broadening of obtained decay rate distributions reflects the disorder in the samples.

No MeSH data available.


Related in: MedlinePlus