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Eu2+-induced enhancement of defect luminescence of ZnS.
- Source :
- Luminescence: Journal of Biological & Chemical Luminescence; Dec2016, Vol. 31 Issue 8, p1532-1535, 4p
- Publication Year :
- 2016
-
Abstract
- The Eu<superscript>2</superscript><superscript>+</superscript>-induced enhancement of defect luminescence of ZnS was studied in this work. While photoluminescence (PL) spectra exhibited 460 nm and 520 nm emissions in both ZnS and ZnS:Eu nanophosphors, different excitation characteristics were shown in their photoluminescence excitation (PLE) spectra. In ZnS nanophosphors, there was no excitation signal in the PLE spectra at the excitation wavelength λ<subscript>ex</subscript> > 337 nm (the bandgap energy 3.68 eV of ZnS); while in ZnS:Eu nanophosphors, two excitation bands appeared that were centered at 365 nm and 410 nm. Compared with ZnS nanophosphors, the 520 nm emission in the PL spectra was relatively enhanced in ZnS:Eu nanophosphors and, furthermore, in ZnS:Eu nanophosphors the 460 nm and 520 nm emissions increased more than 10 times in intensity. The reasons for these differences were analyzed. It is believed that the absorption of Eu<superscript>2</superscript><superscript>+</superscript> intra-ion transition and subsequent energy transfer to sulfur vacancy, led to the relative enhancement of the 520 nm emission in ZnS:Eu nanophosphors. In addition, more importantly, Eu<superscript>2</superscript><superscript>+</superscript> acceptor-bound excitons are formed in ZnS:Eu nanophosphors and their excited levels serve as the intermediate state of electronic relaxation, which decreases non-radiative electronic relaxation and thus increases the intensity of the 460 nm and 520 nm emission dramatically. In summary, the results in this work indicate a new mechanism for the enhancement of defect luminescence of ZnS in Eu<superscript>2</superscript><superscript>+</superscript>-doped ZnS nanophosphors. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 15227235
- Volume :
- 31
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- Luminescence: Journal of Biological & Chemical Luminescence
- Publication Type :
- Academic Journal
- Accession number :
- 119879819
- Full Text :
- https://doi.org/10.1002/bio.3148