Photothermal spectroscopic characterization in core-shell quantum dots nanoparticles

Autor(es)

Pilla, Viviane ; Cruz, Renato A. ; Catunda, Tomaz ; Munin, Egberto ; Pacheco, Marcos. T. T. ; Wetter, NU ; Frejlich, J

• Tipo de documento: Artigo Científico
• Fonte: MAGNETIC FIELDS IN THE UNIVERSE: FROM LABORATORY AND STARS TO PRIMORDIAL STRUCTURES; v. 992, p. 3-pg., 2008-01-01.

Resumo

Thermal Lens (TL) for fluorescence quantum efficiency measurements were performed in CdSe/ZnS core-shell nanoparticles embedded into the poly(methyl methacrylate) (PMMA) and suspended in tetrahydrofuran (THF), chloroform and toluene. TL transient measurements were performed using the mode-mismatched dual-beam (excitation and probe) configuration. A He-Ne laser at lambda(p) = 632.8 nm was used as theprobe beam and either an Ar+ laser (at lambda(e)=476, 488, 501 or 514.5 nm) or a He-Ne laser (at lambda(e),= 594 nm) was used as the excitation beam for solution of nanocrystal suspended in THE The value obtained for the fluorescence quantum efficiency eta was 0.68. Thermo-optical parameters as thermal diffusivity D and the refractive index temperature coefficient dn/dT were determined by TL technique in function of the lambda(e). The values for dn/dT obtained by TL technique corroborate with the results performed with refractometer measurements. (AU)

• Processo FAPESP: 06/01277-2 - Espectroscopia não linear em nanocristais semicondutores funcionalizados para aplicações
• Beneficiário: Viviane Pilla
• Modalidade de apoio: Auxílio à Pesquisa - Regular