Driving emission dynamics of Near-Infrared (NIR) emitting Ln-based materials and their capabilities for multiparametric temperature sensing

• Grant number: 25/14783-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: October 27, 2025
• End date: April 27, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Ana Maria Pires
• Grantee: Leonardo Figueiredo Saraiva
• Supervisor: Markus Suta
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Institution abroad: Heinrich Heine University Düsseldorf (HHU), Germany
• Associated to the scholarship: 23/05718-9 - Multifunctional luminescent films based on down-shifting and up-conversion for anti-counterfeiting application and coated micro-LEDs for display technology, BP.DD

Abstract

The use of photonic materials is fundamentally driven by their remarkable ability to manipulate photons, allowing precise control over light absorption, emission, and modulation. Trivalent lanthanide (Ln3+)-based compounds exploit these principles due to their unique luminescent properties stemming from the partially filled 4f orbitals, which leverage narrow and almost energy-invariant emissions. Since their initial studies, the potential of these materials for developing near-infrared (NIR) emitters has been significant, and their integration with temperature sensing technologies has led to substantial breakthroughs in both biomedical and technological fields. However, NIR emission is prone to several deactivation processes, and the complex ladder-like structure of the Ln3+ energy levels complicates a straightforward interpretation of the excited-state emission dynamics. A deep understanding of these mechanisms allows for the design of increasingly efficient compounds with tailored composition for high-performance devices. This perspective underscores promising directions for exploring NIR emission and illustrates how excited-state dynamics can be harnessed for multiparametric temperature sensing. This rapidly evolving field continues to pursue accuracy and reliability. Advancing NIR emission studies in these phosphors benefits from combining theoretical insights with spectroscopic data, while advanced data analysis algorithms unlock new possibilities in luminescence thermometry. One plausible strategy involves the pairs: Yb3+/Er3+, Yb3+/Tm3+, and Yb3+/Nd3+/Ho3+, which are capable of down-shifting, upconverting and/or downconverting the absorbed photons into NIR radiation, depending on the ion being excited. Furthermore, the closely matched energy levels of these ion pairs enable concentration-tuned emission wavelengths, offering precise control over photonic output. This capability is especially valuable for multimodal systems- an area actively investigated in the candidate's doctoral research. (AU)