Optimized photoluminescence quantum yield in upconversion composites considering the scattering, inner-filter effects, thickness, self-absorption, and temperature

Callum M. S. Jones, Daniel Biner, Stavros Misopoulos, Karl W. Krämer, Jose Marques-Hueso

Research output: Contribution to journalArticlepeer-review

Abstract

Optimizing upconversion (UC) composites is challenging as numerous effects influence their unique emission mechanism. Low scattering mediums increase the number of dopants excited, however, high scattering mediums increase the UC efficiency due to its non-linear power dependency. Scattering also leads to greater thermal effects and emission saturation at lower excitation power density (PD). In this work, a photoluminescence quantum yield (PLQY) increase of 270% was observed when hexagonal NaYF4:(18%)Yb3+,(2%)Er3+ phosphor is in air compared to a refractive index-matched medium. Furthermore, the primary inner-filter effect causes a 94% PLQY decrease when the excitation focal point is moved from the front of the phosphor to 8.4 mm deep. Increasing this effect limits the maximum excitation PD, reduces thermal effects, and leads to emission saturation at higher excitation PDs. Additionally, self-absorption decreases the PLQY as the phosphor's thickness increases from 1 to 9 mm. Finally, in comparison to a cuboid cuvette, a 27% PLQY increase occurs when characterizing the phosphor in a cylindrical cuvette due to a lensing effect of the curved glass, as supported by simulations. Overall, addressing the effects presented in this work is necessary to both maximize UC composite performance as well as report their PLQY more reliably.

Original languageEnglish
Article number13910
JournalScientific Reports
Volume11
Issue number1
DOIs
Publication statusPublished - 6 Jul 2021

ASJC Scopus subject areas

  • General

Fingerprint

Dive into the research topics of 'Optimized photoluminescence quantum yield in upconversion composites considering the scattering, inner-filter effects, thickness, self-absorption, and temperature'. Together they form a unique fingerprint.

Cite this