Local structure analysis of an optically active center in Er-doped ZnO thin film

Ishii, Masashi; Komuro, Shuji; Morikawa, T.; Aoyagi, Yoshinobu

doi:10.1063/1.1355284

Cited by 125 publications

(82 citation statements)

References 39 publications

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“…Provided that PL emission was observed at 980 nm (see inset of No emission was observed from the untreated sample which is in good accordance with the PL results, and may be due to the fact that the surrounding of RE is not adequate to realize up-conversion, and consequently a post-deposition annealing process is necessary. In the case of the annealed samples, the emission intensity of the air and vacuum treatments is in agreement with the one observed in conventional PL spectra: the presence of oxygen enhances RE-related emission/absorption, probably by propitiating the generation of ErO 6 regions [6]. The laser annealed samples show, a very poor up-conversion emission for LAS1 and LAS2, whereas an intense emission is displayed by LAS3, owing to the higher laser power employed.…”

Section: Resultssupporting

confidence: 71%

“…The substitutional doping of Er ions in to the ZnO matrix forming a planar ErO 4 conformation results in a non-optically active state, whereas Er ions fully surrounded by oxygen atoms in a pseudo-octahedron structure with a C 4v symmetry (ErO 6 clusters) are optically active centers that allow the 4f-4f transitions to occur [6]. A thermal annealing is necessary to optically activate the Er ions by changing the Er local structure into the form of ErO 6 clusters, either inside the ZnO matrix or at their grain boundaries [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…A thermal annealing is necessary to optically activate the Er ions by changing the Er local structure into the form of ErO 6 clusters, either inside the ZnO matrix or at their grain boundaries [7,8].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

Lluscà

López-Vidrier

Lauzurica

et al. 2015

Journal of Luminescence

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Section: Resultssupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

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Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

Lluscà

López-Vidrier

Lauzurica

et al. 2015

Journal of Luminescence

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“…Since it was experimentally observed that the rare earth luminescence efficiency at room temperature increases with the band gap of the semiconductor [2], wide band gap materials such as GaN are especially promising for possible applications. Rare earth luminescence from Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm has also been reported in the hexagonal II-VI semiconductor ZnO [3][4][5][6][7][8][9][10][11][12]. Interest in zinc oxide has recently increased due to the fact that its structural and semiconducting properties are similar to hexagonal GaN, but that, in comparison to GaN, highquality single crystals of ZnO are easier to grow [13].…”

Section: Cern-ep Ch-1211 Geneva 23 Switzerlandmentioning

confidence: 99%

“…Several methods for producing RE-doped ZnO have been described in the literature, including sintering [3][4][5], wet-chemical synthesis [6,11], laser ablation [7][8][9][10] and co-deposition following evaporation [12]. However, all these methods result in polycrystalline samples, and there exists evidence that the rare earths accumulate at the grain boundaries of polycrystalline ZnO [4].…”

Section: Cern-ep Ch-1211 Geneva 23 Switzerlandmentioning

confidence: 99%

Implantation site of rare earths in single-crystalline ZnO

Wahl¹,

Rita²,

Correia³

et al. 2003

Applied Physics Letters

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The lattice location of rare earth 167m Er in single-crystalline hexagonal ZnO was studied by means of the emission channeling technique. Following 60-keV room-temperature implantation of the precursor isotope 167 Tm at doses of 1.3−2.8×10 13 cm −2 and annealing up to 900°C, the angular distribution of conversion electrons emitted by the radioactive isotope 167m Er was measured by a position-sensitive electron detector . Interest in zinc oxide has recently increased due to the fact that its structural and semiconducting properties are similar to hexagonal GaN, but that, in comparison to GaN, highquality single crystals of ZnO are easier to grow [13].In analogy with GaN, where the optically active sites of rare earths are considered to be substitutional Ga sites [14,15], optical activity of Er in ZnO is likely to be associated with REs occupying substitutional Zn sites. Several methods for producing RE-doped ZnO have been described in the literature, including sintering [3][4][5], wet-chemical synthesis [6,11], laser ablation [7-10] and co-deposition following evaporation [12]. However, all these methods result in polycrystalline samples, and there exists evidence that the rare earths accumulate at the grain boundaries of polycrystalline ZnO [4]. Ion implantation, on the other hand, which is a widely used method in semiconductor technology for doping single crystals, has so far not been investigated for rare earth doping of ZnO.In this letter we report on the lattice location of ion implanted rare earth atoms in single-crystalline hexagonal ZnO using the emission channeling technique [16]. For that purpose we have measured the angular distribution of conversion electrons emitted by the radioactive isotope 167m Er (t 1/2 = 2.27 s) following implantation of the precursor isotope 167 Tm (t 1/2 = 9.25 d). The recoil energy of the 167 Tm → 167m Er decay is 0.7-0.9 eV only, indicating that the 167m Er lattice site is inherited from 167 Tm. We have already applied this method to study the lattices sites of In order to identify the lattice sites of Er, we have compared the experimental channeling yields to simulated patterns for 167m Er emitter atoms on substitutional Zn sites (S Zn ) and substitutional O sites (S O ) with varying root mean square (rms) displacements. Besides, we also considered a large variety of interstitial sites the location of which has been described in Ref. The electron channeling simulations were carried out with the "many beam" formalism using a number of 20 beams, i.e. representing the electron wave functions by 21×21 Fourier components. In order to describe the crystal structure of ZnO, we adopted two different structural models. While in both models lattice constants of a = 3.2495 Å and c = 5.2069 Å [22] were used, the first approach assumed the Zn-O c-axis bond length to be z = 0.375 c, as in an ideal wurtzite structure. In addition, this approach used isotropic root mean square (rms) displacements of u 1 (Zn) = 0.082 Å and u 1 (O) = 0.085 Å [23], which would correspond to Debye temperatur...

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Controlled Growth and Properties of One‐Dimensional ZnO Nanostructures with Ce as Activator/Dopant

Cheng¹,

Xiao

et al. 2004

Adv Funct Materials

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A large amount of one‐dimensional (1D) Ce‐doped ZnO nanostructures with different morphologies has been successfully synthesized by annealing a polymeric precursor at various temperatures. The evolution of the morphologies and microstructures was investigated by field‐emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), and high‐resolution TEM (HRTEM). The results show that the morphologies vary drastically with increasing synthesis temperature and the photoluminescence (PL) of the products depends on both the synthesis and measurement temperatures. The CeO layer forms first and becomes a catalytic center for the ZnO growth. At a synthesis temperature lower than the boiling point of Zn, Zn and O atoms can stack epitaxially along the CeO catalytic layer and form a bicrystal nanobelt‐like structure with a trapezoid‐like end and a concave growth fault center. At a synthesis temperature higher than the boiling point of Zn, however, nanowires with an incommensurately modulated superstructure are obtained due to the high reaction rate and the formation of a periodic separation of the CeO layer. As for the room‐temperature PL of ZnO, the incorporation of donor Ce leads to the disappearance of the green band and the appearance of a purplish‐blue emission peak, whose position shifts towards the red and whose intensity decreases with increasing synthesis temperature. Analysis of this temperature‐dependent luminescence indicates that the purplish‐blue emission of nanobelts prepared at 850 °C originates from a donor‐bound exciton emission, and, contrary to the nanowires, it undergoes a change from an emission of the electron–hole plasma (EHP) to an emission of the donor‐bound exciton with decreasing measurement temperature.

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Local structure analysis of an optically active center in Er-doped ZnO thin film

Cited by 125 publications

References 39 publications

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

Implantation site of rare earths in single-crystalline ZnO

Controlled Growth and Properties of One‐Dimensional ZnO Nanostructures with Ce as Activator/Dopant

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