Luminescence of TiO2:Pr nanoparticles incorporated in silica aerogel

Amlouk, A.; Mir, L. El; Kraı̈em, S.; Saadoun, M.; Alaya, S.; Pierre, Alain C.

doi:10.1016/j.mseb.2007.07.056

Cited by 27 publications

(15 citation statements)

References 26 publications

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“…3 E CT was chosen 3.8 eV, see arrow 2). Kaczkan et al 22 does not observe any Pr 3+ 4f-4f emission, and Amlouk et al 23 show that the emission from the 3 P 0 level to 3 H 6 and 3 F 4 (arrow 3) in 20-30 nm sized TiO 2 starts to quench above 70K. Such low quenching temperature implies that the 3 P 0 level is located close below E X ; in Fig.…”

Section: Methodsmentioning

confidence: 87%

The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds

Dorenbos

2013

ECS J. Solid State Sci. Technol.

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The vacuum referred binding energy of electrons in the 4f n levels for all divalent and trivalent lanthanide impurity states in TiO 2 , ZnO, SnO 2 , and related compounds MTiO 3 and MSnO 3 (M = Ca 2+ , Sr 2+ , Ba 2+ ) and Ca 2 SnO 4 are presented. They are obtained by collecting data from the literature on the spectroscopy of lanthanide ions, and by combining that data with the chemical shift model. The model provides the energy at the top of the valence band and at the bottom of the conduction band, and it will be shown that those energies are in excellent agreement with what is known from techniques like photo-electron spectroscopy and electrochemical studies. Electronic level diagrams are presented that explain and predict aspects like absence or presence of lanthanide 4f-4f or 5d-4f emissions and the preferred lanthanide valence. © 2013 The Electrochemical Society. [DOI: 10.1149/2.005403jss] All rights reserved.Manuscript received October 17, 2013. Published December 20, 2013 Recently the chemical shift model was introduced 1 for the lanthanide impurities in compounds. By using spectroscopic data for different lanthanides like Ce 3+ , Pr 3+ , Tb 3+ , Eu 3+ , Yb 3+ in the same compound, the model enables to derive the electronic structure with the absolute electron binding energies, i.e., relative to the energy of the electron at rest in vacuum, in all divalent and all trivalent lanthanides.2 It has been applied to about 50 different compounds (fluorides, chlorides, aluminates, phosphates, borates etc.) and full consistency with available experimental data from different fields of science was demonstrated.2-4 It was found that in inorganic compounds based on rare earth cations, like YPO 4 and LaBO 3 , and/or alkaline and/or alkaline earth cations like CaF 2 and CaGa 2 S 4 , the binding energy at the bottom of the conduction band E C is typically near −2 eV. Sc-based compounds like ScBO 3 and ScPO 4 tend to show lower values for E C which was attributed to a large binding energy of electrons in the 3d-shell of Sc 3+ /Sc 2+ that forms the bottom of the conduction band. 4 In this work the model will be applied to TiO 2 , ZnO, SnO 2 , and related ternary compounds. The compounds were selected because of their high importance for many applications.TiO 2 has been and still is thoroughly investigated for its photocatalytic activity and ability for photoelectrochemical water splitting. 5The activity can be enhanced or modified by doping with transition metal or rare earth ions. 6,7 Much is already known on the electronic structure and properties of this compound in its various crystallographic appearances, i.e., rutile-TiO 2 , anatase-TiO 2 , and brookiteTiO 2 . Here we will focus on the anatase-phase. ZnO is an important member of the II-VI semiconductor family. An extensive review on the physical and optical properties of ZnO can be found in Ref. 8. At ambient conditions only the wurtzite phase is thermodynamic stable and all data and schemes in this work will pertain to that phase. SnO 2 has much in common with Zn...

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Section: Methodsmentioning

confidence: 87%

The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds

Dorenbos

2013

ECS J. Solid State Sci. Technol.

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“…The PL spectra, a strong red emission band centered at 643 nm is observed from all samples, is induced by 449 nm excitation. The strong sharp emission peak around 643 nm is attributed to 3 P 0 → 3 F 2 transition, while the weak red emission located at around 616 nm is owing to 3 P 0 → 3 H 6 transition, which is induced by the lack of inversion symmetry at the Pr 3+ ions sites [12]. The Pr 3+ -related narrow band emission at about 643 nm corresponding to the intense absorption of 449 nm suggests an effective host-to-activator energy transfer.…”

Section: Resultsmentioning

confidence: 99%

The investigation of optical properties by doping halogen in the BaMoO4:Pr3+ phosphor system

Yang

et al. 2009

Journal of Alloys and Compounds

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“…For the TiO 2 sputtering times longer than 12 min only an orange emission at 650 nm is observed and its intensity increases as the TiO 2 -shell layer thickness increases further. As regards the emission band at 650 nm, there are two reports: one is on that of ZnS [8] and the other on that of Pr 3 + -doped TiO 2 incorporated in silica matrix [24], yet the orange emission in our nanowire samples seems to have an origin different from either of the two. The rapid increase in the emission intensity with an increase in the TiO 2 -shell layer thickness suggests that the emission at 650 nm does not originate from deep levels in the ZnS cores but from the deep levels like Zn and S dopants generated in the TiO 2 shells by annealing.…”

Section: Resultsmentioning

confidence: 69%

“…Besides these, an orange emission band centered at 650 nm has been reported for Pr 3 + -doped TiO 2 incorporated in silica matrix [24]. The violet emission is known to be attributed to self-trapped excitons localized on TiO 6 octahedra [14,15], while the blue emission originates from oxygen (O) vacancies [15,16] or surface states [17,18].…”

Section: Introductionmentioning

confidence: 97%

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Enhancement in the photoluminescence of ZnS nanowires by TiO2 coating and thermal annealing

Jin

Kim

et al. 2010

Journal of Luminescence

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Luminescence of TiO2:Pr nanoparticles incorporated in silica aerogel

Cited by 27 publications

References 26 publications

The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds

The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds

The investigation of optical properties by doping halogen in the BaMoO4:Pr3+ phosphor system

Enhancement in the photoluminescence of ZnS nanowires by TiO2 coating and thermal annealing

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Luminescence of TiO2:Pr nanoparticles incorporated in silica aerogel

Cited by 27 publications

References 26 publications

The Electronic Structure of Lanthanide Impurities in TiO2, ZnO, SnO2, and Related Compounds

The Electronic Structure of Lanthanide Impurities in TiO2, ZnO, SnO2, and Related Compounds

The investigation of optical properties by doping halogen in the BaMoO4:Pr3+ phosphor system

Enhancement in the photoluminescence of ZnS nanowires by TiO2 coating and thermal annealing

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The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds

The Electronic Structure of Lanthanide Impurities in TiO₂, ZnO, SnO₂, and Related Compounds