Limits...
Defect induced changes on the excitation transfer dynamics in ZnS/Mn nanowires.

Kaiser U, Chen L, Geburt S, Ronning C, Heimbrodt W - Nanoscale Res Lett (2011)

Bottom Line: The transients of the Mn-related luminescence can be quantitatively described on the basis of a modified Förster model accounting for reduced dimensionality.Here, we confirm this modified Förster model by varying the number of killer centers systematically.The temporal behavior of the internal Mn2+ (3d5) luminescence is recorded on a time scale covering almost four orders of magnitude.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Material Sciences Center, Philipps-University of Marburg, Renthof 5, 35032 Marburg, Germany. limei.klar@physik.uni-marburg.de.

ABSTRACT
Transients of Mn internal 3d5 luminescence in ZnS/Mn nanowires are strongly non-exponential. This non-exponential decay arises from an excitation transfer from the Mn ions to so-called killer centers, i.e., non-radiative defects in the nanostructures and is strongly related to the interplay of the characteristic length scales of the sample such as the spatial extensions, the distance between killer centers, and the distance between Mn ions. The transients of the Mn-related luminescence can be quantitatively described on the basis of a modified Förster model accounting for reduced dimensionality. Here, we confirm this modified Förster model by varying the number of killer centers systematically. Additional defects were introduced into the ZnS/Mn nanowire samples by irradiation with neon ions and by varying the Mn implantation or the annealing temperature. The temporal behavior of the internal Mn2+ (3d5) luminescence is recorded on a time scale covering almost four orders of magnitude. A correlation between defect concentration and decay behavior of the internal Mn2+ (3d5) luminescence is established and the energy transfer processes in the system of localized Mn ions and the killer centers within ZnS/Mn nanostructures is confirmed. If the excitation transfer between Mn ions and killer centers as well as migration effects between Mn ions are accounted for, and the correct effective dimensionality of the system is used in the model, one is able to describe the decay curves of ZnS/Mn nanostructures in the entire time window.

No MeSH data available.


Related in: MedlinePlus

The experimental data and the fitted curves from Mn PL transients. ZnS/Mn wire samples with a Mn concentration 0.28 at.% which were implanted at temperatures of (a) 300°C and (b) 600°C as well as samples with additional neon irradiation by a total ion fluence of (c) 4.38·1012 cm-2 and of (d) 4.38·1013 cm-2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211286&req=5

Figure 5: The experimental data and the fitted curves from Mn PL transients. ZnS/Mn wire samples with a Mn concentration 0.28 at.% which were implanted at temperatures of (a) 300°C and (b) 600°C as well as samples with additional neon irradiation by a total ion fluence of (c) 4.38·1012 cm-2 and of (d) 4.38·1013 cm-2.

Mentions: Figure 5 depicts the transients of various ZnS/Mn samples with a Mn concentration of 0.28 at.% but different killer center densities. The variation of the killer center densities is achieved by two different approaches. The curves (a) and (b) show Mn PL decay curves of ZnS/Mn nanowires annealed at 300°C and 600°C, respectively (approach 2). The curves (c) and (d) show the nanowires which were annealed at 600°C followed additional neon irradiation (approach 3) with a total ion fluence of 4.38·1012 cm-2 (curve c) and ion fluence of 4.38·1013 cm-2 (curve d).


Defect induced changes on the excitation transfer dynamics in ZnS/Mn nanowires.

Kaiser U, Chen L, Geburt S, Ronning C, Heimbrodt W - Nanoscale Res Lett (2011)

The experimental data and the fitted curves from Mn PL transients. ZnS/Mn wire samples with a Mn concentration 0.28 at.% which were implanted at temperatures of (a) 300°C and (b) 600°C as well as samples with additional neon irradiation by a total ion fluence of (c) 4.38·1012 cm-2 and of (d) 4.38·1013 cm-2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211286&req=5

Figure 5: The experimental data and the fitted curves from Mn PL transients. ZnS/Mn wire samples with a Mn concentration 0.28 at.% which were implanted at temperatures of (a) 300°C and (b) 600°C as well as samples with additional neon irradiation by a total ion fluence of (c) 4.38·1012 cm-2 and of (d) 4.38·1013 cm-2.
Mentions: Figure 5 depicts the transients of various ZnS/Mn samples with a Mn concentration of 0.28 at.% but different killer center densities. The variation of the killer center densities is achieved by two different approaches. The curves (a) and (b) show Mn PL decay curves of ZnS/Mn nanowires annealed at 300°C and 600°C, respectively (approach 2). The curves (c) and (d) show the nanowires which were annealed at 600°C followed additional neon irradiation (approach 3) with a total ion fluence of 4.38·1012 cm-2 (curve c) and ion fluence of 4.38·1013 cm-2 (curve d).

Bottom Line: The transients of the Mn-related luminescence can be quantitatively described on the basis of a modified Förster model accounting for reduced dimensionality.Here, we confirm this modified Förster model by varying the number of killer centers systematically.The temporal behavior of the internal Mn2+ (3d5) luminescence is recorded on a time scale covering almost four orders of magnitude.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Material Sciences Center, Philipps-University of Marburg, Renthof 5, 35032 Marburg, Germany. limei.klar@physik.uni-marburg.de.

ABSTRACT
Transients of Mn internal 3d5 luminescence in ZnS/Mn nanowires are strongly non-exponential. This non-exponential decay arises from an excitation transfer from the Mn ions to so-called killer centers, i.e., non-radiative defects in the nanostructures and is strongly related to the interplay of the characteristic length scales of the sample such as the spatial extensions, the distance between killer centers, and the distance between Mn ions. The transients of the Mn-related luminescence can be quantitatively described on the basis of a modified Förster model accounting for reduced dimensionality. Here, we confirm this modified Förster model by varying the number of killer centers systematically. Additional defects were introduced into the ZnS/Mn nanowire samples by irradiation with neon ions and by varying the Mn implantation or the annealing temperature. The temporal behavior of the internal Mn2+ (3d5) luminescence is recorded on a time scale covering almost four orders of magnitude. A correlation between defect concentration and decay behavior of the internal Mn2+ (3d5) luminescence is established and the energy transfer processes in the system of localized Mn ions and the killer centers within ZnS/Mn nanostructures is confirmed. If the excitation transfer between Mn ions and killer centers as well as migration effects between Mn ions are accounted for, and the correct effective dimensionality of the system is used in the model, one is able to describe the decay curves of ZnS/Mn nanostructures in the entire time window.

No MeSH data available.


Related in: MedlinePlus