Frenzel, Florian and Wuerth, Christian and Dukhno, Oleksii and Przybilla, Frederic and Wiesholler, Lisa M. and Muhr, Verena and Hirsch, Thomas and Mely, Yves and Resch-Genger, Ute (2021) Multiband emission from single beta-NaYF4(Yb,Er) nanoparticles at high excitation power densities and comparison to ensemble studies. NANO RESEARCH, 14 (11). pp. 4107-4115. ISSN 1998-0124, 1998-0000
Full text not available from this repository. (Request a copy)Abstract
Ensemble and single particle studies of the excitation power density (P)-dependent upconversion luminescence (UCL) of core and core-shell beta-NaYF4:Yb,Er upconversion nanoparticles (UCNPs) doped with 20% Yb3+ and 1% or 3% Er3+ performed over a P regime of 6 orders of magnitude reveal an increasing contribution of the emission from high energy Er3+ levels at P > 1 kW/cm(2). This changes the overall emission color from initially green over yellow to white. While initially the green and with increasing P the red emission dominate in ensemble measurements at P < 1 kW/cm(2), the increasing population of higher Er3+ energy levels by multiphotonic processes at higher P in single particle studies results in a multitude of emission bands in the ultraviolet/visible/near infrared (UV/vis/NIR) accompanied by a decreased contribution of the red luminescence. Based upon a thorough analysis of the P-dependence of UCL, the emission bands activated at high P were grouped and assigned to 2-3, 3-4, and 4 photonic processes involving energy transfer (ET), excited-state absorption (ESA), cross-relaxation (CR), back energy transfer (BET), and non-radiative relaxation processes (nRP). This underlines the P-tunability of UCNP brightness and color and highlights the potential of P-dependent measurements for mechanistic studies required to manifest the population pathways of the different Er3+ levels.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ; upconversion luminescence; single nanoparticle study; high power excitation; emission color; luminescence decay kinetics |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik > Chemo- und Biosensorik (Prof. Antje J. Bäumner, formerly Prof. Wolfbeis) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 Sep 2022 06:57 |
| Last Modified: | 20 Sep 2022 06:57 |
| URI: | https://pred.uni-regensburg.de/id/eprint/47602 |
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