Nanoparticle characterization of Er-doped SnO2 pellets obtained with different pH of colloidal suspension

Abstract

SnO 2 :2 at. %Er xerogel samples were obtained by sol-gel technique from colloidal suspensions with distinct pHs. The evaluation of critical regions inside the nanocrystallite is fundamental for the interpretation of the influence of pH on the emission data. In this way, the nanocrystal depletion layer thickness was obtained with the help of photoluminescence, Raman, X-ray diffraction, and field-emission gun scanning electron microscopy measurements. It was observed that acid suspensions (pH < 7) lead to high surface disorder in which a larger number of cross-linked bonds Sn-O-Sn among nanoparticles are present. For these samples, the nanoparticle depletion layer is larger as compared to samples obtained from other pH. Photoluminescence measurement in the near infrared region indicates that the emission intensity of the transition 4 I 13/2 ! 4 I 15/2 is also influenced by the pH of the starting colloidal suspension, generating peaks more or less broadened, depending on location of Er 3þ ions in the SnO 2 lattice (high or low symmetry sites). V C 2013 AIP Publishing LLC. [http://dx

Revealing Interplay of Defects in SnO2 Quantum Dots for Blue Luminescence and Selective Trace Ammonia Detection at Room Temperature

“…The "D" peak is described to arise due to large surface defects such as O V of SnO 2 . 15,43 Hence, the Raman study also points out an enhanced crystalline feature for the S-8 compared to the QDs, which has significant structural defects. For further investigation on defects in SnO 2 NPs, EELS and XAS studies are carried out.…”

“…Notably, no such Raman modes are observed in S-1 NPs except for a huge broad peak at 573 cm –1 (D), which diminishes with increased growth temperature (Figure SI4). The “D” peak is described to arise due to large surface defects such as O V of SnO 2 . , Hence, the Raman study also points out an enhanced crystalline feature for the S-8 compared to the QDs, which has significant structural defects. For further investigation on defects in SnO 2 NPs, EELS and XAS studies are carried out.…”

On the Use of Surfactant for Precursor Solution Processing and Influence on the Properties of Tin Dioxide Thin Films

“…The water is kept in circulation to maintain the hydrolysis process over approximately two weeks. After this period, the pH is about 7, and the contents of the membrane bags are transferred to a beaker, for evaporation of part of the solvent and increase in viscosity, and subsequent film deposition [21]. SnO2 thin films were prepared from two colloidal suspensions with 0.27M of SnO2, however 1% of the volume of Triton X-100 surfactant was added to one of them.…”

Influência do lantânio nas propriedades estruturais do SrSnO3

“…Uma vez que a emissão fotoluminescente, FL, é devida à fase inorgânica desordenada, à medida que diminui o carbono pelo aumento da temperatura de queima em atmosfera oxidante, a emissão FL aumenta. No entanto, vários são os trabalhos que apresentam resultados mostrando que este grau de desordem apresenta um limite, ou seja, à medida que se aumenta a temperatura de calcinação e/ou a concentração de impurezas, responsáveis pela desordem estrutural, observa-se um aumento do grau de cristalinidade do sistema e o decréscimo da FL [15,[19][20][21]. A diminuição da intensidade fotoluminescente para o sistema contendo 10% em mol de lantânio pode estar associada ao possível ordenamento do material, tal como discutido para filmes de PbTiO 3 dopados com lantânio [16].…”