Luminescence of Eu3+, Eu2+, or Mn2+-doped åkermanite as a thermometer and luminophore for LEDs

• Grant number: 25/07426-0
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: July 31, 2025
• End date: January 28, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Marian Rosaly Davolos
• Grantee: Juliana de Macedo Tavares
• Supervisor: Luis Antonio Ferreira Martins Dias Carlos
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Institution abroad: Universidade de Aveiro (UA), Portugal
• Associated to the scholarship: 24/02532-4 - Akermanite structure doped with different ions and its applications as luminescent materials, BP.MS

Abstract

Semi-invasive or non-invasive temperature sensors have attracted considerable interest in recent years, with those based on luminescence being one of them; and to get around the problems of the green gap of LEDs and the cool white light, luminescent materials emitting green and red lights are excellent candidates for this. Given this, this project aims to study materials based on the Ca2MgSi2O7 (åkermanite) matrix, stable at high temperatures, doped with Eu3+ and/or Eu2+, or Mn2+ ions, aiming at their application in luminescent thermometry and luminophores for LEDs (light-emitting diodes). For thermometry, the Eu3+-doped system should be further explored as a ratiometric sensor using the intensities of the electronic transitions 5D1 -> 7F1 and 5D0 -> 7F0, 5D1 -> 7F1 and 5D0 -> 7F2, and 5D1 <- 7F1 and 5D1 <- 7F0, in addition to investigating the lifetime variation and assembling temperature sensor for solutions. With the Ca2MgSi2O7:Mn2+ material, the ratios between the emission bands are more sensitive at temperatures above 85 °C. The data processing of this sample and the interpretation of the phenomena that occur with heating, such as energy transfer, still need to be investigated. In parallel, the combined emission of Eu2+ and Eu3+ ions will be evaluated, which, when excited in the blue range (460-466 nm) of an LED chip, should result in emissions in the green and red regions of the spectrum, which combined with the semiconductor emission, would generate white light. Therefore, based on this material, the aim is to develop a prototype of a warm white light LED. The research will be conducted in a group with extensive theoretical and experimental experience in luminescence, luminescent temperature sensors, and applications in LED devices.