Synthesis of trivalent rare earths co-doped LaAlO3:Cr3+ nanoparticles with infrared persistent luminescence

• Grant number: 16/06736-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2016
• End date: July 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Lucas Carvalho Veloso Rodrigues
• Grantee: Douglas Lourenço Fritzen
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The majority of persistent luminescent materials has its emission at blue-green region (400 - 550 nm). Near Infrared (NIR) emitters are rare and often very expensive or inefficient. These NIR emitting materials have great potential for applications on energy storage and bioimaging. For an efficient application of NIR emitters, their luminescence should persist for hours after ceasing the charging with visible light irradiation. On this project, we aim to develop nanoparticles of La1-xRxAl1-yCryO3 (R: trivalent rare earth ion i.e. Y, Ce-Lu) with persistent luminescence at near infrared region. The nanoparticles will be obtained with combustion synthesis, where high temperatures can be reached in few seconds and nanoparticles are easily obtained. To guarantee NIR emission, Cr3+ will be used as dopant and R3+ co-dopants will be applied aiming to intensify the persistent luminescence of the material. For optimizations and characterizations of these nanomaterials, X-Ray diffractions, infrared vibrational spectroscopy and scanning electron microscopy analyses will be done. The X-ray absorption spectroscopies of the optimized samples will be also measured at Brazilian Synchrotron Light Laboratory (Laboratório Nacional de Luz Síncrotron - LNLS), at XANES and EXAFS regions. The photoluminescence study will be done with UV-irradiated Excitation and emission as well as persistent luminescence emission spectra. The excited state lifetime as well the persistent luminescence decay time will be analyzed to study the feeding of persistent luminescence as well as the defects. The defects that in fact contribute for the persistent luminescence will be analyzed with thermoluminescence characterization.