Enhancing multiphoton upconversion through interfacial energy transfer in multilayered nanoparticles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32132529.
- Also identified by DOI 10.1038/s41467-020-14879-9 and PMC identifier 7055352.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Photon upconversion in lanthanide-doped upconversion nanoparticles offers a wide variety of applications including deep-tissue biophotonics. However, the upconversion luminescence and efficiency, especially involving multiple photons, is still limited by the concentration quenching effect. Here, we demonstrate a multilayered core-shell-shell structure for lanthanide doped NaYF<sub>4</sub>, where Er<sup>3+</sup> activators and Yb<sup>3+</sup> sensitizers are spatially separated, which can enhance the multiphoton emission from Er<sup>3+</sup> by 100-fold compared with the multiphoton emission from canonical core-shell nanocrystals. This difference is due to the excitation energy transfer at the interface between activator core and sensitizer shell being unexpectedly efficient, as revealed by the structural and temperature dependence of the multiphoton upconversion luminescence. Therefore, the concentration quenching is suppressed via alleviation of cross-relaxation between the activator and the sensitizer, resulting in a high quantum yield of up to 6.34% for this layered structure. These findings will enable versatile design of multiphoton upconverting nanoparticles overcoming the conventional limitation.