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Luminescence of colloidal CdSe/ZnS nanoparticles: high sensitivity to solvent phase transitions.

Antipov A, Bell M, Yasar M, Mitin V, Scharmach W, Swihart M, Verevkin A, Sergeev A - Nanoscale Res Lett (2011)

Bottom Line: We investigate nanosecond photoluminescence processes in colloidal core/shell CdSe/ZnS nanoparticles dissolved in water and found strong sensitivity of luminescence to the solvent state.First of all, the luminescence intensity substantially (approximately 50%) increases near the transition.The observed effects are associated with the reconstruction of ligands near the ice/water phase transition.

View Article: PubMed Central - HTML - PubMed

Affiliation: Electrical Engineering Department, University at Buffalo, Buffalo, NY 14260, USA. vmitin@buffalo.edu.

ABSTRACT
We investigate nanosecond photoluminescence processes in colloidal core/shell CdSe/ZnS nanoparticles dissolved in water and found strong sensitivity of luminescence to the solvent state. Several pronounced changes have been observed in the narrow temperature interval near the water melting point. First of all, the luminescence intensity substantially (approximately 50%) increases near the transition. In a large temperature scale, the energy peak of the photoluminescence decreases with temperature due to temperature dependence of the energy gap. Near the melting point, the peak shows N-type dependence with the maximal changes of approximately 30 meV. The line width increases with temperature and also shows N-type dependence near the melting point. The observed effects are associated with the reconstruction of ligands near the ice/water phase transition.

No MeSH data available.


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PL FWHM of in-liquid CdSe/ZnS NPs near the water freezing point.
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Figure 4: PL FWHM of in-liquid CdSe/ZnS NPs near the water freezing point.

Mentions: PL full width at half maximum (FWHM) for in-liquid CdSe/ZnS NPs in the temperature range of T = 240-290 K is shown on Figure 4. Another feature is observed near the water freezing point. The FWHM increases by approximately 40 meV, from approximately 0.12 eV to approximately 0.16 eV, as the temperature changes from 260 to 270 K. However, PL shows substantially different behavior at low and high temperatures. The FWHM decreases much faster in the temperature range T = 270-290 K than that at T = 240-260 K. Also, it is important to notice that the FWHM for dry NPs does not show peculiarities within the temperature range T = 240-290 K.


Luminescence of colloidal CdSe/ZnS nanoparticles: high sensitivity to solvent phase transitions.

Antipov A, Bell M, Yasar M, Mitin V, Scharmach W, Swihart M, Verevkin A, Sergeev A - Nanoscale Res Lett (2011)

PL FWHM of in-liquid CdSe/ZnS NPs near the water freezing point.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211190&req=5

Figure 4: PL FWHM of in-liquid CdSe/ZnS NPs near the water freezing point.
Mentions: PL full width at half maximum (FWHM) for in-liquid CdSe/ZnS NPs in the temperature range of T = 240-290 K is shown on Figure 4. Another feature is observed near the water freezing point. The FWHM increases by approximately 40 meV, from approximately 0.12 eV to approximately 0.16 eV, as the temperature changes from 260 to 270 K. However, PL shows substantially different behavior at low and high temperatures. The FWHM decreases much faster in the temperature range T = 270-290 K than that at T = 240-260 K. Also, it is important to notice that the FWHM for dry NPs does not show peculiarities within the temperature range T = 240-290 K.

Bottom Line: We investigate nanosecond photoluminescence processes in colloidal core/shell CdSe/ZnS nanoparticles dissolved in water and found strong sensitivity of luminescence to the solvent state.First of all, the luminescence intensity substantially (approximately 50%) increases near the transition.The observed effects are associated with the reconstruction of ligands near the ice/water phase transition.

View Article: PubMed Central - HTML - PubMed

Affiliation: Electrical Engineering Department, University at Buffalo, Buffalo, NY 14260, USA. vmitin@buffalo.edu.

ABSTRACT
We investigate nanosecond photoluminescence processes in colloidal core/shell CdSe/ZnS nanoparticles dissolved in water and found strong sensitivity of luminescence to the solvent state. Several pronounced changes have been observed in the narrow temperature interval near the water melting point. First of all, the luminescence intensity substantially (approximately 50%) increases near the transition. In a large temperature scale, the energy peak of the photoluminescence decreases with temperature due to temperature dependence of the energy gap. Near the melting point, the peak shows N-type dependence with the maximal changes of approximately 30 meV. The line width increases with temperature and also shows N-type dependence near the melting point. The observed effects are associated with the reconstruction of ligands near the ice/water phase transition.

No MeSH data available.


Related in: MedlinePlus