Filmes delgados luminescentes obtidos a partir de hidroxicarbonatos de ítrio ativados por európio ou térbio

Niyama, Emy; Alencar, Anselmo Colombo de; Vila, Ligia Delgado da; Stucchi, Elizabeth Berwerth; Davolos, Marian Rosaly

doi:10.1590/s0100-40422004000200002

Cited by 7 publications

(6 citation statements)

References 6 publications

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“…The use of natural products such as organic dyes in solar cells offers promising prospects for the advance of this technology, since photoexcitable dyes are substances that cede electrons easily, while the use of synthetic dyes involves several problems, such as their synthesis, purification and use, as well as the fact that they require rare metals [5][6][7][8] . Cyanidin is an organic dye of the flavonoid class found in leaves and fruits and responsible for the colors of various vegetal tissues, which has been studied for application as a sensitizer of this type of solar cell [7][8][9][10][11] (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Sol-Gel TiO2 thin films sensitized with the mulberry pigment cyanidin

et al. 2007

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TiO2 films have various applications, among them solar cells and photodegradation of pollutants. In this study, we investigated TiO2 films functionalized with the organic dye cyanidin extracted from black mulberry (Morus nigra). The TiO2 was functionalized by the sol-gel method and the film was deposited on glass substrates by dip-coating. Our aim was to investigate the interaction between the semiconductor and the dye, as well as the influence of the velocity and number of deposits on the characteristics of the film. Using ultraviolet-visible spectroscopy, we observed a shift from the maximum absorption band at 545 nm for the dye’s ethanol solution to 595 nm for the film, indicating interaction of the cyanidin with the TiO2. The absorption spectra in the infrared region of the functionalized TiO2 particles showed bands characteristic of the oxide and indicated their interaction with the dye. Using profilometry and m-line techniques, we found that the films presented thicknesses in the order of 100 nm. A SEM analysis confirmed the high density of the films

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Section: Introductionmentioning

confidence: 99%

Sol-Gel TiO2 thin films sensitized with the mulberry pigment cyanidin

et al. 2007

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“…Além do mais, são amplamente encontrados no cotidiano, da luz verde dos vagalumes aos tubos catódicos da televisão, passando pelas placas de sinalização e pela identificação de manchas de sangue. [1][2][3][4] A propriedade fotoluminescente apresenta uma relação intrínseca com a organização estrutural do material. As transições energéticas acontecem pela recombinação do par elétron-buraco, dentro do band gap, entre as bandas de condução e valência.…”

Section: Introductionunclassified

Influência do Método de Síntese e do Tratamento Térmico na Fotoluminescência de Nanocompósitos de Céria Dopada com Gadolínio/Zircônia

et al. 2020

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Neste trabalho, os nanocompósitos de interesse foram preparados, utilizando-se o Método dos Precursores Poliméricos, por meio do qual se prepararam os citratos de céria dopados com 10, 15 e 20% de gadolínio, e encapsularam-se com 3% em mol de ZrO2, em diferentes temperaturas. Para a caracterização dos materiais obtidos, utilizaram-se as técnicas de Difração de Raios X e Emissão Fotoluminescente. Verifiou-se que a alta concentração do dopante ocasiona tanto a melhoria na emissão, pela adição de defeitos, quanto a diminuição, pelo quenching da emissão. O aumento na temperatura de tratamento térmico também reduz a emissão, uma vez que diminui a quantidade de defeitos.

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“…The sol-gel process is based on hydrolysis and condensation reactions [4][5][6] . Properties such as the viscosity and gelation time are essential for the formation of the hybrid matrices (organic-inorganic) and have demonstrated the versatility of this methodology for the preparation of monoliths, films, fibers, powders, and nanoparticles 3,[7][8][9][10][11][12][13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

Incorporation of europium III complex into nanoparticles and films obtained by the Sol-Gel methodology

et al. 2010

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The sol-gel process is very effective for the preparation of new materials with potential applications in optics, sensors, catalyst supports, coatings, and specialty inorganic polymers that can be used as hosts for the accommodation of organic molecules. The low temperature employed in the process is the main advantage of this methodology. In this work, the europium (III) complex with 1,10-phenantroline was prepared, and this luminescent complex was incorporated into silica nanoparticles and films by the sol-gel process. The nanoparticles were obtained by the modified Stöber methodology. The films were obtained by the dip-coating technique, at different deposition rates and numbers of layers. The nanoparticles and films were characterized by photoluminescence, thermal analysis, and Raman and infrared spectroscopies. Characterization revealed that the europium (III) complex was not affected upon incorporation into the nanoparticles and films, opening a new field for the application of these materials

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Filmes delgados luminescentes obtidos a partir de hidroxicarbonatos de ítrio ativados por európio ou térbio

Cited by 7 publications

References 6 publications

Sol-Gel TiO2 thin films sensitized with the mulberry pigment cyanidin

Sol-Gel TiO2 thin films sensitized with the mulberry pigment cyanidin

Influência do Método de Síntese e do Tratamento Térmico na Fotoluminescência de Nanocompósitos de Céria Dopada com Gadolínio/Zircônia

Incorporation of europium III complex into nanoparticles and films obtained by the Sol-Gel methodology

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