"Lanthanide doped Alkali/alkaline earth niobates and germanates: Studies of Persistent Luminescence to Active planar waveguide".

• Grant number: 23/02852-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): June 01, 2023
• Effective date (End): March 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Rogéria Rocha Gonçalves
• Grantee: Vítor dos Santos de Souza
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers, AP.TEM

Abstract

This research project focuses on the development of luminescent materials based on lanthanide doped alkali/alkaline earth germanate and niobate, with visible and near infrared (IR) emission, in the form of active planar waveguides and particulate powders, seeking multifunctional applications that can act in photonics, such as optical amplifiers for telecommunications systems and energy concentrators / converters to increased efficiency in solar cells and materials exhibiting persistent luminescence. The materials will be prepared using the sol-gel methodology, and other synthetic routes depending on the application, from precursors alkoxides and oxides of Nb2O5 and GeO2 and carbonates of alkali/alkaline earth metals. In the case of niobium, a focus will be given to the use of national mining precursors (CBMM) to increase the added value of a national product, where Brazil has an extremely relevant role in the world scenario of niobium extraction. Preparation and characterization as a function of alkali metal/alkaline earth composition, TR3+ ion doping and heat treatment. Therefore, a systematic study of the optical, structural, morphological and spectroscopic (vibrational and electronic) properties will be carried out. Luminescence in the visible region will also be studied, not only as a competitive process with near-IR emission, but also aiming at the great potential resulting from upconversion processes, spontaneous emission (downshifting) for application in thermometry and the study of luminescence persistent as a function of the structure of matter. Studies on the dependence of luminescent properties on doping will be explored, resulting in different crystalline structures depending on the concentration and nature of the rare earth dopant ion and the alkali/alkaline earth metal used. Optical studies of thin films such as waveguide features, thickness per layer and refractive index will be studied, in addition to spectroscopic studies of emission in the so-called third window of telecommunications in the near infrared region.