Advanced Engineering of NIR-Rechargeable Persistent Luminescent Glass Composites : From Bulk, to Scaffold and Fiber Architectures
Santos Magalhães, Evellyn (2026)
Tampere University
2026
Teknisten tieteiden tohtoriohjelma - Doctoral Programme in Engineering Sciences
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Väitöspäivä
2026-03-27
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-03-4480-1
https://urn.fi/URN:ISBN:978-952-03-4480-1
Tiivistelmä
The interaction between light and matter lies at the heart of photonic innovation, enabling technologies that span from biomedical imaging to security devices, just to cite few applications. This thesis presents a study on new glass-based materials that exhibit persistent luminescence after near-infrared (NIR) charging.
By embedding persistent luminescent phosphors into phosphate, silicate and tellurite glass matrices, we demonstrate that new glass-based materials can be prepared in bulk, scaffold, and fiber architecture while still emitting green afterglow not only after UV charging but also after NIR charging. This green afterglow after NIR charging is achieved by coupling Yb³⁺/Tm³⁺ pair with SrAl2O4:Eu3+, Dy³+ phosphors. The former absorbs NIR photons and emits blue light via upconversion processes, while the latter stores and gradually releases energy as green afterglow. Extending this concept to additive manufacturing, we developed 3D printed biophotonic scaffolds using robocasting. These scaffolds retain their photonic functionality post-fabrication and serve as active platforms for in-situ drug delivery as demonstrated using Phthal Azobenzene Iperoxo (PAI), the photoisomerization of which was triggered by the (blue and green) light emitted from the scaffold under 980 nm pumping. We also explore the possibility of generating green persistent luminescence from a newly developed optical fiber. A tellurite glass matrix codoped with Yb³⁺ and Tm³⁺ was selected for its high refractive index, low phonon energy, and excellent thermal stability and was prepared with embedded SrAl2O4:Eu3+, Dy³+phosphors. Despite the presence of the phosphors in the glass matrix and of surface defects, the fiber retains its light-guiding capability and emits green afterglow after being charged with near-infrared light, revealing promising pathways for new flexible, multi-level, and compact anti-counterfeiting technologies, for example.
This thesis advances an innovative and interdisciplinary framework for developing novel photonic systems, positioning persistent luminescence triggered by near-infrared excitation as a promising mechanism for applications in sensing, signaling, and therapeutic technologies.
By embedding persistent luminescent phosphors into phosphate, silicate and tellurite glass matrices, we demonstrate that new glass-based materials can be prepared in bulk, scaffold, and fiber architecture while still emitting green afterglow not only after UV charging but also after NIR charging. This green afterglow after NIR charging is achieved by coupling Yb³⁺/Tm³⁺ pair with SrAl2O4:Eu3+, Dy³+ phosphors. The former absorbs NIR photons and emits blue light via upconversion processes, while the latter stores and gradually releases energy as green afterglow. Extending this concept to additive manufacturing, we developed 3D printed biophotonic scaffolds using robocasting. These scaffolds retain their photonic functionality post-fabrication and serve as active platforms for in-situ drug delivery as demonstrated using Phthal Azobenzene Iperoxo (PAI), the photoisomerization of which was triggered by the (blue and green) light emitted from the scaffold under 980 nm pumping. We also explore the possibility of generating green persistent luminescence from a newly developed optical fiber. A tellurite glass matrix codoped with Yb³⁺ and Tm³⁺ was selected for its high refractive index, low phonon energy, and excellent thermal stability and was prepared with embedded SrAl2O4:Eu3+, Dy³+phosphors. Despite the presence of the phosphors in the glass matrix and of surface defects, the fiber retains its light-guiding capability and emits green afterglow after being charged with near-infrared light, revealing promising pathways for new flexible, multi-level, and compact anti-counterfeiting technologies, for example.
This thesis advances an innovative and interdisciplinary framework for developing novel photonic systems, positioning persistent luminescence triggered by near-infrared excitation as a promising mechanism for applications in sensing, signaling, and therapeutic technologies.
Kokoelmat
- Väitöskirjat [5337]