Luminescent phosphors and films based on Ln3+ exhibiting multimodal emission properties for photonic applications: Investigating their multifunctionalities

• Grant number: 24/06434-7
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: September 30, 2024
• End date: March 28, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Ana Maria Pires
• Grantee: Leonardo Figueiredo Saraiva
• Supervisor: Luis Antonio Ferreira Martins Dias Carlos
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Institution abroad: Universidade de Aveiro (UA), Portugal
• 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 underpinned by their remarkable ability to manipulate the behavior of photons, enabling precise control over light absorption, emission, and modulation. Accordingly, trivalent lanthanide (Ln3+)-based compounds harness these principles due to their unique luminescence features stemming from the partially filled 4f orbitals, leveraging narrow and almost energy-invariant emission. Recent studies have demonstrated the potential of Ln3+-based materials in optical storage and molecular logic, where combining both fields showcases a remarkable advancement that has not been foreseen. Additionally, the physical stimulus required to produce the logical outputs, such as heat, opens the possibility of using the same materials for luminescence thermometry. This field has been booming over the last few years for providing accurate non-contact temperature readings. This perspective demonstrates the prospects within the realm of photonic Ln3+-based materials. However, much of the research conducted thus far regarding this class of compounds has focused on single-modal luminescence, limiting the scope of potential applications. To advance this field, the attainment of multimodal luminescence is a desirable attribute, allowing the expansion of the horizons of applications. To achieve this aim, combining down-shifting and upconversion luminescence is a feasible approach. One plausible strategy involves dispersing phosphors, such as SrY2O4:Ln3+ (Ln = Eu, Tb, Nd, Yb, Er) or GdYO3:Ln3+ (Ln = Eu, Nd, Yb, Er) with these individual features in a polymeric matrix, like poly(methyl methacrylate), namely PMMA, to form a luminescent film, these systems being the subject of the candidate's current doctoral research project (FAPESP 2023/05718-9). Therefore, a thorough optical investigation from an experimental and theoretical point of view of these phosphors and their polymeric films is essential to unlock their potential for subsequent applications.