Optical characteristics of Er3+–Yb3+ doped SnO2 xerogels

Morais, Evandro Augusto de; Ribeiro, Sandra Fogaça Rosa; Scalvi, Luís Vicente de Andrade; Santilli, Celso Valentim; Ruggiero, Ligia de Oliveira; Pulcinelli, Sandra Helena; Messaddeq, Younès

doi:10.1016/s0925-8388(02)00344-4

Cited by 56 publications

(43 citation statements)

References 7 publications

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“…2(c). In a previous paper [12], it was verified that codoping with Yb 3+ is efficient only for Er 3+ ions located at 2 figure 1. Besides, generation of ctron-hole pairs from the SnO 2 matrix was provided th excitation with 328nm.…”

Section: Methodsmentioning

confidence: 87%

“…2(a). It is well known that emission from substitutional sites is easily observed via bandto-band excitation of SnO 2 [12]. Then, the large band observed by PLE is a strong indication that Er 3+ enters into the lattice, in substitution to Sn atoms.…”

Section: Methodsmentioning

confidence: 93%

“…In the inset, it is seen PLE with fixed emission at 1540nm. A recent investigation of PL spectra [12] of SnO 2 :Er,Yb xerogels with doping concentration of 0.1at% yield information on Er localization in the matrix. Two families of Er sites were found in SnO 2 : substitutional to Sn 4+ and segregated at boundary layer.…”

Section: Methodsmentioning

confidence: 99%

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Analysis of Er3+ incorporation in SnO2 by optical investigation

Morais¹,

Scalvi²,

Martins³

et al. 2006

Braz. J. Phys.

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Er 3+ emission in the wide bandgap matrix SnO 2 is observed either through a direct Er ion excitation process as well as by an indirect process, through energy transfer in samples codoped with Yb 3+ ions. Electron-hole generation in the tin dioxide matrix is also used to promote rare-earth ion excitation. Photoluminescence spectra as function of temperature indicate a slight decrease in the emission intensity with temperature increase, yielding low activation energy, about 3.8meV, since the emission even at room temperature is rather considerable.

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Section: Methodsmentioning

confidence: 87%

Section: Methodsmentioning

confidence: 93%

See 1 more Smart Citation

Analysis of Er3+ incorporation in SnO2 by optical investigation

Morais¹,

Scalvi²,

Martins³

et al. 2006

Braz. J. Phys.

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“…Some Stark peaks present an inhomogeneous splitting due to electric field variation in different sites occupied by the Er 3þ ion in the SnO 2 nanocrystal. 36,37 When the Er 3þ neighborhood changes, the electric field also changes due to the random neighbor distribution, characteristic of materials with nanoscopic crystallites, generating small variations in the positions of the Stark levels. Figure 10 presents some details concerning the PL spectra acquired at 9 K, related to Er 3þ transitions of Table III. The effect of the different pH of the starting solution on the Stark levels can be verified through the broadening of the peak width.…”

Section: Resultsmentioning

confidence: 99%

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

Ravaro¹,

Scalvi

Tabata

et al. 2013

Journal of Applied Physics

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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

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“…Then, the result shown in Figure 5 for the pH 4 film suggests that the limiting pH value for improving electrical properties depends also on the doping nature. The Er 3+ doping is located mainly at particles surface due to the low solubility 34 . Then, during the formation of cross-linked bond Sn-O-Sn, the Er 3+ may influence the process, leading to shorter potential barriers.…”

Section: Low Temperature Electrical Characterization Of Thin Filmsmentioning

confidence: 99%

Influence of pH of colloidal suspension on the electrical conductivity of SnO2 thin films deposited via Sol-Gel-Dip-Coating

Ravaro

Scalvi

2011

Mat. Res.

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Tin dioxide (SnO 2 ) thin films are deposited by the dip-coating technique from colloidal suspensions prepared with distinct pH through the sol-gel method. The decrease of the pH contributes to the destruction of an electrical layer adjacent to particles in solution, leading to a high degree of aggregation among these particles due to the generation of cross-linked bonds (Sn-O-Sn) between them. The aggregation affects the electrical properties of films, because the pH variation produces particle with distinct sizes in the film. Undoped samples prepared from pH 6 leads to the highest conductivity among the investigated undoped samples, in agreement with X-ray diffractograms, which indicate higher crystallinity for lower pH. Arrhenius plot evaluated from temperature dependent conductivity data leads to activation energies of the deepest level between 67 to 140 meV, for the films prepared from suspensions with pH 6 to 11. The most probable explanation for this variation in the conductivity and activation energy is related to distinct potential barriers between grains, due to distinct packing caused by cross-linked bonds formed during suspension phase. Characterization of samples lightly doped with Er 3+ confirms that acid pH leads to higher conductivity, but the highest conduction takes place at even lower pH when compared to undoped thin films.

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Optical characteristics of Er3+–Yb3+ doped SnO2 xerogels

Cited by 56 publications

References 7 publications

Analysis of Er3+ incorporation in SnO2 by optical investigation

Analysis of Er3+ incorporation in SnO2 by optical investigation

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

Influence of pH of colloidal suspension on the electrical conductivity of SnO2 thin films deposited via Sol-Gel-Dip-Coating

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