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Updated: Jan 29, 2026
13:51
Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications
Published on: November 10, 2017
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Quasi-thresholdless Photon Upconversion in Metal-Organic Framework Nanocrystals.
F Meinardi1, M Ballabio1, N Yanai2
1Dipartimento di Scienza dei Materiali , Università degli Studi Milano-Bicocca , via R. Cozzi 53 , 20125 Milano , Italy.
Nano Letters
|February 7, 2019
Summary
Photon upconversion using sensitized triplet-triplet annihilation (sTTA) in metal-organic framework nanocrystals (nMOFs) achieves 100% yield. These thresholdless annihilators enhance solar devices by efficiently converting low-energy photons.
Area of Science:
- Materials Science
- Photochemistry
- Nanotechnology
Background:
- Photon upconversion is crucial for enhancing solar device performance by utilizing low-energy photons.
- Sensitized triplet-triplet annihilation (sTTA) is a key mechanism for photon upconversion.
- Metal-organic framework nanocrystals (nMOFs) offer potential as light-managing materials.
Purpose of the Study:
- To demonstrate 100% triplet-triplet annihilation (TTA) yield in nMOFs for efficient photon upconversion.
- To develop a kinetic model for upconversion dynamics in nanocrystal ensembles.
- To establish a method for optimizing nMOF dimensions and concentrations for solar applications.
Main Methods:
- Fabrication of nMOFs with sizes smaller than the exciton diffusion length.
- Development of a kinetic model to describe upconversion dynamics and define threshold excitation intensity (Ith).
- Creation of a nanocomposite material using nMOFs for experimental validation.
Main Results:
- nMOFs smaller than exciton diffusion length exhibit 100% TTA yield, acting as thresholdless single-unit annihilators.
- The kinetic model accurately predicts the threshold excitation intensity (Ith) based on excitation energy distribution.
- The fabricated nanocomposite demonstrated efficient upconversion under low solar irradiance levels.
Conclusions:
- Fast exciton diffusion in sub-exciton diffusion length nMOFs enables highly efficient, condition-independent upconversion.
- The developed kinetic model provides a predictive tool for designing optimal nMOF-based light-managing materials.
- This approach meets the requirements for practical solar energy technologies by efficiently harvesting unused photons.
Keywords:
Photon upconversionmetal−organic frameworksnanocompositenanocrystalstriplet−triplet annihilationMore Related Videos
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