Synthesis and characterization of PKAl glasses co-doped with Dy3+/Tb3+for application in solid state lighting devices

Author(s)

Brito, K. O. ; Neto, O. C. Silva ; Dantas, N. F. ; Lodi, T. A. ; Pedrochi, F. ; Steimacher, A.

• Document type: Journal article
• Source: Optical Materials; v. 165, p. 10-pg., 2025-05-06.

Abstract

In this work, PKAl oxyfluorophosphate glasses (P2O5-KF-Al2O3) doped with Dy3+ ions and co-doped with Dy3+ and Tb3+ ions were studied. The samples were prepared using the melting-quenching technique. The samples were prepared with a fixed concentration of Dy2O3 (0.5 mol%), while the Tb4O7 concentration varied from 0.25 % to 0.75 mol%. Results of structural, optical and spectroscopic properties were discussed. The XRD confirmed the amorphous structure of the glasses. An increase in the density and molar volume values of the samples was observed with the concentration of Dy2O3 and Tb4O7. The FTIR spectra revealed the characteristic bands of vibrations of the phosphate groups, as well as AlO6 and AlO4. The optical absorption spectra exhibited characteristic bands of Dy3+ and Tb3+ ions, with an increase in the intensities of the Tb3+ absorption bands with Tb4O7 concentration. The excitation spectra show the best excitation region for Dy3+ and Tb3+ ions, with the most intense bands at 350 nm and 375 nm, respectively. In the photoluminescence spectra, the characteristic emissions of both ions were detected, outstanding the peaks at 575 nm for Dy3+ and 545 nm for Tb3+. An increase in PL intensity of Tb3+ bands was observed upon excitation at 350, 375, and 405 nm, while a decrease in PL intensity of Dy3+ bands was detected, suggesting an energy transfer process with Dy3+ acting as the energy donor. Furthermore, the increase in Tb4O7 concentration favored energy transfer processes with an increase in transfer rate up to 12.5 %. Quantum yield results indicate an increase with increasing Tb4O7 content, ranging from 22 to 42 %. The results suggest that the series of PKAl glasses doped and co-doped with Dy3+ and Tb3+ ions can be candidates for use in the development of solid-state lighting devices. (AU)

• FAPESP's process: 23/09906-4 - Development of new methodologies for the manufacture of optical fibers from exotic glasses
• Grantee: Thiago Augusto Lodi
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• FAPESP's process: 23/01625-6 - Development of new methodologies for the manufacture of optical fibers from exotic glasses
• Grantee: Marcelo Nalin
• Support Opportunities: Regular Research Grants