Persistent luminescence of heavy metal-free glass composites for white lighting

• Grant number: 22/07667-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: August 01, 2022
• End date: July 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Andrea Simone Stucchi de Camargo Alvarez Bernardez
• Grantee: Leonnam Gotardo Merizio
• Supervisor: Mika Lastusaari
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Turku, Finland
• Associated to the scholarship: 19/21770-5 - Luminescent materials incorporated to glasses: new composites for application in safety lighting and radiation detection, BP.PD

Abstract

This project addresses the research internship at the Intelligent Materials Chemistry (IMC) group at the University of Turku in Finland, through the BEPE/FAPESP Postdoctoral program for 12 months. This project aims to develop new efficient and heavy metal-free white persistent luminescence (PersL) materials embedded into glass hosts. Solid-state white lighting has called attention due to its extensive range of applications. However, most single-phase white emission compounds are composed of organic molecules, which can present photodegradation after a long period of UV exposure. Inorganic materials are generally much more stable, however, the most efficient compounds are based on heavy metals, such as rare earth (RE), Cr, Cd, and Ge, which can increase the production costs and cause adverse effects to health. In this context, the persistent luminescent materials are considered very important, due to their capacity to absorb and store energy and yield light emissions for hours. The no needing for a continuous excitation source makes these materials very ideal for emergency signaling, such as the broadly employed exit signs. Nevertheless, an efficient PersL white light emitter is extremely rare. The Ti Doped Li-Hackmanite ((Li,Na)8Al6Si6O24(Cl,S)2:Ti) has been presented as a low-cost and efficient alternative for the classic RE-doped compounds, with a PersL emission observable for more than 100 h. However, this material is obtained in powder form, which limits its use. The incorporation of this and other powder compounds into stable glass hosts opens possibilities for several applications.Considering these aspects, the Intelligent Materials Chemistry group at the University of Turku, under the leadership of Professor Dr. Mika Lastusaari, is considered one of the most important groups focused on luminescent materials and correlated areas. Also, the work will be developed in collaboration with Professor Dr. Laeticia Petit, leader of the Photonic Glasses group at Tampere University. The knowledge, networking, and experience acquired through this internship will deeply impact technological and scientific development, and bring benefits not only to the candidate but also to his home group LEMAF at IFSC. (AU)