New methodologies for the synthesis of glass-ceramics combining plasmon-enhanced upconversion and persistent luminescence

• Grant number: 24/21790-4
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2025
• End date: September 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Lucas Carvalho Veloso Rodrigues
• Grantee: Nataly Soares Santos
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/11983-4 - Spectroscopy signal enhancement: nanomaterials, theory, and computer simulation, AP.TEM

Abstract

Materials for light storage can release previously stored energy in the form of light under different stimuli like thermal, optical or mechanical energies. When the main stimulus is the room temperature thermal energy, they are called Persistent Luminescence materials and are vastly applied in glow-in-the-dark features or non-electrical safety signage. They also hold great potential to be applied in photocatalysis, in vivo bioimaging, theragnostic, or stress sensing applications. This phenomenon occurs due to the trapping of charge carriers in defects during light absorption (light, UV radiation, electron beam, plasma beam, X-ray, etc.). Despite the existence of several efficient materials, there is a big gap in the field of near-infrared induced persistent luminescence materials. Recently our group developed an approach combining an efficient upconversion materials with a efficient green excited persistent luminescence material allowing the generation of persistent luminescence under NIR irradiation. However, the upconversion phenomenon has low efficiency and the radiative energy transfer process used in the approach requires that the upconversion and persistent luminescence particles are close to each other. This project seeks to produce glass-ceramics combining upconversion and persistent luminescent nanoparticles with the aim to produce composites that can emit light for hours after NIR irradiation. To improve the upconversion efficiency, gold and/or silver nanoparticles will be combined with the upconversion materials. This efficiency improvement will be caused by the plasmon enhancement of the upconversion effect that has been studied in the last decade, even if its mechanisms are not well comprehended. For this, the first challenge is the synthesis of dispersible nanosized persistent luminescence materials outside or inside the glass. The project seeks to produce the composites with two different approaches: i) the melting of the glass combined with the nanoparticles and ii) the crystallization of the persistent luminescence and upconversion materials in the glass matrices. Finally, one last goal of this project is to implement new characterization methodologies for persistent glasses using the Sirius beamlines Carnauba, Quati and Imbuia.