Effects of the Pechini's modified synthetic route on structural and photophysical properties of Eu3+ or Tb3+-doped LaAlO3

Author(s)

Garcia, A. B. S. ^{[1, 2, 3]} ; Bispo-Jr, A. G. ; Lima, S. A. M. ^[2] ; Pires, A. M. ^{[1, 2, 3]}

Affiliation

^[1] Sao Paulo State Univ UNESP, Inst Chem, BR-14800900 Araraquara, SP - Brazil

^[2] Sao Paulo State Univ Unesp, Sch Technol & Sci, R Roberto Simonsen 305, BR-19060900 Presidente Prudente, SP - Brazil

^[3] Sao Paulo State Univ Unesp, Inst Biosci Humanities & Exact Sci, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Document type: Journal article
• Source: Materials Research Bulletin; v. 143, NOV 2021.
• Web of Science Citations: 0

Abstract

Herein, it is reported the Pechini's synthesis of LaAlO3:Ln(3+) (Ln = Eu3+ or Tb3+) varying doping concentration from 1 to 9 at.% to evaluate its influence on structure and luminescence. Sub-micrometric, high-crystalline and monophasic samples with crystallite size smaller than 61 nm were synthesized with activators replacing slightly distorted LaO12 polyhedra, and occupying two non-equivalent local sites on the surface, and inside them. Upon UV excitation, Eu3+-doped phosphors emit at 620 nm while Tb3+ ones exhibit dominant wavelength within the green spectral region. The excited state lifetimes lie within 2.5-3.4 ms, and as doping percentage increases, luminescence quenching mediated by exchange coupling energy transfer occurs, leading to the 3 and the 7% as the optimal Eu3+ and Tb(3+)concentrations, respectively. Finally, our proposed route increases the Eu3+ D-5(0)-> F-7(2) transition relative intensity, compared with others reported, ensuring that this method brings a breakthrough in the optical performance of LaAlO3-based phosphors. (AU)

• FAPESP's process: 19/23763-6 - Triplet state direct excitation on trivalent lanthanide complexes
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/13688-1 - Lanthanum aluminate in the planning of functionalized luminescent core@shell systems containing the Eu3+ and Tb3+ ions for application in light converting devices
• Grantee: Alessandro Bruno Silva Garcia
• Support Opportunities: Scholarships in Brazil - Master