Macquarie University
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Exploring energy distribution of photon upconversion and downconversion luminescence in lanthanide-doped nanoparticles

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posted on 2022-03-28, 16:09 authored by Qiang Wang
Lanthanide-doped nanoparticles exhibiting short-wavelength infrared (SWIR) luminescence have emerged as promising luminescent probes for advanced in vivo imaging with enhanced tissue penetration, sensitivity and resolution. However, a key bottleneck remains in the limited luminescence efficiency, which fundamentally stems from the complicated energy levels and transition pathways possessed by lanthanide emitters. This work aims to perform a spectroscopic study on several lanthanide-doped nanoparticles to illustrate their detailed photon transfer and energy distribution processes. A luminescence spectroscopy system is first set up, allowing characterisation of broad emission spectra spanning the ultraviolet to the SWIR region. Then, Er- and Tm-activated nanoparticles are examined, and the energy transition processes corresponding to individual characteristic emission peaks are interpreted based on their measured energy level diagrams alongside the excitation-emission relations. Finally, the influence of doping concentrations as well as additional co-dopants are investigated to explore potential approaches to regulating the energy distribution. The results obtained here may be exploited to engineer lanthanide-doped nanoparticles with concentrated SWIR emission for efficient in vivo optical imaging in the future.


Table of Contents

1. Introduction -- 2. Instrumentation, experimental methods -- 3. Probing the competition between photoluminescence pathways in lanthanide-doped nanoparticles -- 4. Exploring the influence of doping on the energy distribution in lanthanide nanoparticles -- 5. Conclusion and perspectives.


Bibliography: pages 55-60 Theoretical thesis.

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


MRes, Macquarie University, Faculty of Science and Engineering, Department of Physics and Astronomy

Department, Centre or School

Department of Physics and Astronomy

Year of Award


Principal Supervisor

Yiqing Lu


Copyright Qiang Wang 2018. Copyright disclaimer:




1 online resource (v, 60 pages : illustrations)

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