Investigation of the persistent luminescence energy migration using high-end thermoluminescence and electron microscopy methods

• Grant number: 18/09403-4
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: September 06, 2018
• End date: September 05, 2019
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Marcia Carvalho de Abreu Fantini
• Grantee: Jose Miranda de Carvalho Junior
• Supervisor: Philippe Smet
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Ghent University (UGent), Belgium
• Associated to the scholarship: 17/05195-5 - Structure-property relations of inorganic luminescent materials obtained by microwave-assisted synthesis method, BP.PD

Abstract

Persistent luminescence (PeL) materials are attracting strong scientific interest nowadays due to their ability of storage of luminous energy for considerable periods of time. This stored energy can be used in a variety of applications, from emergency lighting to medical diagnoses and imaging. However, the improvement of the PeL materials is based on the try and error basis, mostly changing the chemical composition and (co-)dopants. The mechanisms of PeL require further understanding, in order to improve the design of the materials yielding better energy storage and consequently high efficiencies. Energy storage in the PeL materials occurs in the lattice defects that act as charge carrier traps forming long-lived states that can be emptied only after absorption of available thermal (kT) or optical (h½) energy. Despite the fact that the mechanisms of PeL phenomenon are reasonably well developed from the spectroscopic point of view, the energy storage is still a missing part. The spatial distribution of the defects related to the activator ions is necessary to unveil the mechanisms of energy storage. This project aims to use high-end thermoluminescence (TL) methods allied with scanning electron transmission microscopy (STEM) to shed light on the energy migration processes in crystalline PeL material. The modeling of the phenomenon can lead to more sophisticated mechanisms and possibly more efficient materials.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE CARVALHO, JOSE MIRANDA; VAN DER HEGGEN, DAVID; MARTIN, LISA I. D. J.; SMET, PHILIPPE F.. Microwave-assisted synthesis followed by a reduction step: making persistent phosphors with a large storage capacity. DALTON TRANSACTIONS, v. 49, n. 14, p. 4518-4527, APR 14 2020. (17/05195-5, 18/09403-4)