Intrinsic Time-Tunable Emissions in Core-Shell Upconverting Nanoparticle Systems.

Angew Chem Int Ed Engl. 2019 Jun 04;:

Authors: Tessitore G, Maurizio SL, Sabri T, Capobianco JA

Abstract

Color-tunable luminescence has been extensively investigated in upconverting nanoparticles for diverse applications, each exploiting emissions in different spectral regions. Manipulation of the emission wavelength is accomplished by varying the composition of the luminescent material or the characteristics of the excitation source. Here we propose core-shell ß-NaGdF4: Tm3+, Yb3+/ ß-NaGdF4: Tb3+ nanoparticles as intrinsic time-tunable luminescent materials. The time dependency of the emission wavelength only depends on the different decay time of the two emitters, without additional variation of the dopant concentration or pumping source. The time-tunable emission was recorded with a commercially available camera. The dynamics of the emissions is thoroughly investigated, and we established that the energy transfer from the 1D2 excited state of Tm3+ ions to the higher energy excited states of Tb3+ ions to be the principal mechanism to the population of the 5D4 level for the Tb3+ ions.

PMID: 31161694 [PubMed - as supplied by publisher]