Trabalho apresentado em evento
Efficient UV-visible upconversion luminescence and thermal effects in terbium-ytterbium codoped fluorogermanate vitroceramic
Fecha
2008-06-13Registro en:
Proceedings of SPIE - The International Society for Optical Engineering, v. 6875.
0277-786X
10.1117/12.759685
2-s2.0-44849118448
6446047463034654
2998503841917815
0000-0003-3286-9440
Autor
Universidade Federal Rural de Pernambuco (UFRPE)
Universidade Estadual Paulista (Unesp)
Resumen
Cooperative energy-transfer upconversion luminescence in Tb 3+/Yb 3+-codoped PbGeO 3-PbF 2-CdF 2 vitroceramic and its precursor glass under resonant and off-resonance infrared excitation, is investigated. Bright UV-visible emission signals around 384, 415, 438 nm, and 473-490, 545, 587, and 623 nm, identified as due to the 5D 3( 5G 6 → 7F J(J=6,5,4) and 5D 4 → 7F J(J=6,5,4,3) transitions, respectively, were readily observed. The results indicate that cooperative energy-transfer between ytterbium and terbium ions followed by excited-state absorption are the dominant upconversion excitation mechanisms herein involved. The comparison of the upconversion process in a vitroceramic sample and its glassy precursor revealed that the former present much higher upconversion efficiency. The dependence of the upconversion emission upon pump power, temperature, and doping content is also examined.