Quantum cutting and up-conversion investigations in Pr3+/Yb3+ co-doped oxyfluoro-tellurite glasses

Author(s)

Rajesh, D. ; Dousti, M. Reza ; Amjad, Raja J. ; de Camargo, A. S. S.

• Document type: Journal article
• Source: Journal of Non-Crystalline Solids; v. 450, p. 149-155, OCT 15 2016.
• Web of Science Citations: 14

Abstract

In this work we have investigated quantum cutting, up-conversion and downconversion processes in new Pr3+/Yb3+ co-doped transparent oxyfluoro-tellurite glasses with chemical composition TeO2-ZnO-YF3-NaF-0.5Pr(2)O(3)-xYb(2)O(3) (x = 0.25, 0.5, 0.75 and 1.0 mol%). In the down-conversion process, Pr3+-Yb3+ co-doped samples present emission in the visible (Pr3+: P-3(0) -> F-3(2) transition, 640 nm) and in the infrared (Yb3+:F-2(5/2) -> F-2(712), 980 nm) spectral regions upon excitation at 440 nm. The luminescence decay time of the emitting levels were obtained in co-doped samples as a function of Yb3+ concentration and the results confirmed the occurrence of energy transfer from Pr3+ to Yb3+ via a combination of two different cross relaxation processes: (1) Pr3+: P-3(0) -> (1)G(4) to Yb3+: F-2(7/2) -> F-2(5/2) and (2) Pr3+: D-1(2) -> F-3(4) to Yb3+: F-2(7/2) -> F-2(5/2). Furthermore due to the reverse-energy transfer mechanism from Yb3+ F-2(5/2) level to- Pr3+ (1)G(4) level, luminescence intensity quenching was observed for the F-2(5/2) -> F-2(7/2) transition at 980 nm, for Yb3+ concentrations higher than 0.5 mol%. The energy transfer efficiency was estimated from the intensity ratios and decay times associated to the P-3(0) -> F-3(2) transition, and it reached 66% for a glass co-doped with 0.5Pr(3+) and 1.0Yb(3+) (mol%). The results indicate that these glasses are potential candidates for manipulation of the solar spectrum, via up-conversion and downconversion processes, in order to increase the absorption efficiency of currently used c-Si photovoltaic solar cells. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 15/10713-0 - Investigations of up and down conversion of energy in glass and glass ceramics of rare earth ions doped tellurite for solar cell applications
• Grantee: Rajesh Dagupati
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/08434-5 - Fluoroindate and tellurite glasses doped with rare earth ions and metallic nanoparticles for enhanced solar cell efficiency by sunlight down-shifting and upconversion
• Grantee: Andrea Simone Stucchi de Camargo Alvarez Bernardez
• Support type: Research Grants - Visiting Researcher Grant - International