Formation mechanisms of ZnO nanocrystals embedded in an amorphous Zn2xSi1−xO2 layer due to sputtering and annealing

Shin, Jae–Heon; Lee, Jun Young; No, Young Soo; Kim, T.W.; Choi, W. K.

doi:10.1016/j.jallcom.2010.12.021

Cited by 3 publications

(3 citation statements)

References 29 publications

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“…We see that the average sizes and the standard deviations decrease with increasing temperature. The decrease of the average sizes of ZnO-NCs with increasing annealing temperature is presumably because of the formation of Zn 2 SiO 4 at the ZnO and SiO 2 interfaces [6]. The reduction of the corresponding standard deviation indicates that the average sizes become more uniform with increasing temperature.…”

Section: Resultsmentioning

confidence: 99%

Annealing temperature and environment effects on ZnO nanocrystals embedded in SiO2: a photoluminescence and TEM study

et al. 2013

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We report on efficient ZnO nanocrystal (ZnO-NC) emission in the near-UV region. We show that luminescence from ZnO nanocrystals embedded in a SiO2 matrix can vary significantly as a function of the annealing temperature from 450°C to 700°C. We manage to correlate the emission of the ZnO nanocrystals embedded in SiO2 thin films with transmission electron microscopy images in order to optimize the fabrication process. Emission can be explained using two main contributions, near-band-edge emission (UV range) and defect-related emissions (visible). Both contributions over 500°C are found to be size dependent in intensity due to a decrease of the absorption cross section. For the smallest-size nanocrystals, UV emission can only be accounted for using a blueshifted UV contribution as compared to the ZnO band gap. In order to further optimize the emission properties, we have studied different annealing atmospheres under oxygen and under argon gas. We conclude that a softer annealing temperature at 450°C but with longer annealing time under oxygen is the most preferable scenario in order to improve near-UV emission of the ZnO nanocrystals embedded in an SiO2 matrix.

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Section: Resultsmentioning

confidence: 99%

Annealing temperature and environment effects on ZnO nanocrystals embedded in SiO2: a photoluminescence and TEM study

et al. 2013

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“…By the same token, when the annealing temperature increases, the bandwidth of the broad emission from ZnO-nc decreases thus resulting in decreasing the spectral overlap between the ZnO-nc broadband emission and the Eu 3+ ion excitation, and therefore a reduction in energy transfer from the ZnO-nc to the Eu 3+ ions leading to a reduction in the red emission intensity from the Eu 3+ ions. In addition, the energy transfer from ZnO-nc to the Eu 3+ ions is inhibited in the samples annealed at 550 o C and 600 o C due to the possible formation of Zn 2 SiO 4 at the surface of the ZnO-nc [159]. Formation of Zn 2 SiO 4 reduces the size of ZnO-nc causing reduction of PL emission [159] from the ZnO-nc and also results in increase in distance between ZnO-nc and Eu 3+ ion which results in reduces energy transfer from the ZnO-nc to the Eu 3+ ions.…”

Section: To Obtain the Optimum Red Emission Intensity From The Eu 3+mentioning

confidence: 99%

“…In addition, the energy transfer from ZnO-nc to the Eu 3+ ions is inhibited in the samples annealed at 550 o C and 600 o C due to the possible formation of Zn 2 SiO 4 at the surface of the ZnO-nc [159]. Formation of Zn 2 SiO 4 reduces the size of ZnO-nc causing reduction of PL emission [159] from the ZnO-nc and also results in increase in distance between ZnO-nc and Eu 3+ ion which results in reduces energy transfer from the ZnO-nc to the Eu 3+ ions. In this work, the optimum RTP annealing temperature has been found to be 450 o C.…”

Section: To Obtain the Optimum Red Emission Intensity From The Eu 3+mentioning

confidence: 99%

Efficient energy transfer from zinc oxide nanocrystals to europium (3+) and terbium (3+) ions embedded in an oxide matrix

Mangalam¹

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Study of energy transfer mechanism from ZnO nanocrystals to Eu3+ ions

Mangalam¹,

Pita²,

Couteau³

2016

Nanoscale Res Lett

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In this work, we investigate the efficient energy transfer occurring between ZnO nanocrystals (ZnO-nc) and europium (Eu3+) ions embedded in a SiO2 matrix prepared using the sol-gel technique. We show that a strong red emission was observed at 614 nm when the ZnO-nc were excited using a continuous optical excitation at 325 nm. This emission is due to the radiative 5D0 → 7F2 de-excitation of the Eu3+ ions and has been conclusively shown to be due to the energy transfer from the excited ZnO-nc to the Eu3+ ions. The photoluminescence excitation spectra are also examined in this work to confirm the energy transfer from ZnO-nc to the Eu3+ ions. Furthermore, we study various de-excitation processes from the excited ZnO-nc and their contribution to the energy transfer to Eu3+ ions. We also report the optimum fabrication process for maximum red emission at 614 nm from the samples where we show a strong dependence on the annealing temperature and the Eu3+ concentration in the sample. The maximum red emission is observed with 12 mol% Eu3+ annealed at 450 °C. This work provides a better understanding of the energy transfer mechanism from ZnO-nc to Eu3+ ions and is important for applications in photonics, especially for light emitting devices.

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Formation mechanisms of ZnO nanocrystals embedded in an amorphous Zn2xSi1−xO2 layer due to sputtering and annealing

Cited by 3 publications

References 29 publications

Annealing temperature and environment effects on ZnO nanocrystals embedded in SiO2: a photoluminescence and TEM study

Annealing temperature and environment effects on ZnO nanocrystals embedded in SiO2: a photoluminescence and TEM study

Efficient energy transfer from zinc oxide nanocrystals to europium (3+) and terbium (3+) ions embedded in an oxide matrix

Study of energy transfer mechanism from ZnO nanocrystals to Eu3+ ions

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