Vidros de germanato com nanopartículas metálicas e semicondutoras dopados com terras-raras para aplicações em fotônica. / Germanate glasses containing metalic an semiconductor nanoparticles dopes with rare-earth ions for photonic aplicattions.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

01/09/2010

RESUMO

This work presents a spectroscopic study about Eu3+, Nd3+ and Er3+ rare-earth doped germanate glasses containing metallic and semiconductor nanoparticles (NPs) aiming the development of new materials for photonic applications. These glasses have a large transmission window (400-4500 nm), high refractive index (~ 1.9), low phonon energy (700 cm-1), high mechanic resistance and chemical durability. Transmission Electronic Microscopy analysis was performed to verify the metallic and semiconductor NPs nucleation, and indicated the presence of metallic and semiconductor NPs. X ray fluorescence by energy dispersive spectroscopic (EDS) and electron diffraction analysis showed the chemical nature of the NPs. Optic absorption measurement proved the trivalent incorporation of the rare-earth ions, the responsible phenomenon for the luminescence of the glasses that allowed the measurement of the absorption bands related to the superficial plasmon resonance. Emission measurements were performed with different procedures, related to nature of the rare-earth. High emission bands of Eu3+ were measured related to the 7F J (J=0 to 6) ->5D 0 transitions; emission bands associated to the frequency upconversion of Er3+ in 530, 550 and 670nm related to the 2H 11/2 ->4I 15/2, 4S 3/2 ->4I 15/2 e 4F 9/2 ->4I 15/2 transitions were observed, and as well as emission bands of Nd3+ in 900, 1076 and 1350 nm related with the 4F 3/2 ->4I 9/2, 4F 3/2 ->4I 11/2 e 4F 3/2 ->4I 13/2 transitions. A significant enhancement of the red light luminescence of Eu3+ was observed in the samples containing silver, gold, and silver together with gold NPs. For the samples containing silicon NPs it was observed a considerable enhancement of the frequency upconversion emission of the erbium. The luminescence enhancement of the samples with metallic NPs is due to the enhancement of the local field nearby the rare-earth ions and/or to the energy transfer between the NPs and the rare-earth ions. The luminescence enhancement of the samples with semiconductor NPs are due to the efficient energy transfer between the NPs and the rare-earth ions originated from the excitons recombination inside the semiconductor NPs. Therefore, the presence of the NPs plays an important role on the luminescence enhancement, allowing de development of new materials for nanophotonic applications.

ASSUNTO(S)

Érbio erbium európio europium germanate glasses Íons de terras-raras metallic nanoparticles nanopartículas metálicas nanopartículas semicondutoras neodímio neodymium rare-earth ions semiconductor nanoparticles vidros.

ACESSO AO ARTIGO

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