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A Step Beyond BRET: Fluorescence by Unbound Excitation from Luminescence FUEL
Published on: May 23, 2014
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Microlens array enhanced upconversion luminescence at low excitation irradiance
Qingyun Liu1, Haichun Liu2, Deyang Li3
1Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, Stockholm, Sweden. hagren@kth.se haichun@kth.se and School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, P.R. China. chenguanying@hit.edu.cn.
Nanoscale
|July 18, 2019
Summary
Microlens arrays (MLAs) boost lanthanide-doped upconversion nanoparticle (UCNP) luminescence intensity by over 100x. This spatial light modulation technique enhances UCNP applications in bioimaging and photovoltaics.
Area of Science:
- Materials Science
- Nanotechnology
- Photonics
Background:
- Lanthanide-doped upconversion nanoparticles (UCNPs) exhibit low luminescence intensity at low excitation, limiting their applications.
- Upconversion luminescence (UCL) intensity is nonlinearly dependent on excitation irradiance.
Purpose of the Study:
- To enhance UCL intensity from UCNPs using microlens arrays (MLAs).
- To investigate the impact of MLAs on multicolored UCL from core/shell UCNPs.
- To demonstrate the potential of MLA-enhanced UCNPs in devices like solar cells.
Main Methods:
- Utilized polymeric microlens arrays (MLAs) as spatial light modulators.
- Investigated multicolored UCL from NaYF4:Yb3+,Er3+@NaYF4:Yb3+,Nd3+ and NaYF4:Yb3+,Tm3+@NaYF4:Yb3+,Nd3+ core/shell UCNPs.
- Employed ray tracing simulations to understand light field manipulation by MLAs.
Main Results:
- Achieved over one order of magnitude increase in UCL intensity using MLAs.
- Observed distinct enhancement factors for green, red (Er3+), and blue (Tm3+) UCL bands.
- Demonstrated a 225-fold amplification of Tm3+ UCL at low excitation irradiance.
Conclusions:
- MLAs effectively enhance UCL intensity by spatially confining excitation light.
- The MLA method significantly improves the performance of UCNP-based devices.
- This technique offers a promising pathway for advancing UCNP applications in various fields.
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