Energy transfer between the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.gif" overflow="scroll"><mml:msup><mml:mrow><mml:mi>Eu</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math> dipole and aggregate centers in CsBr:Eu crystals

Zorenko, Yu.; Turchak, R.; Voznjak, T.

doi:10.1016/j.radmeas.2007.01.065

Cited by 13 publications

(6 citation statements)

References 11 publications

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“…To investigate the exciton recombination dynamics of CsBr:Eu 2+ NCs, time‐resolved PL spectra were measured and the results are depicted in Figure d. The PL decay dynamics of CsBr:Eu 2+ NCs were monoexponential with lifetime of 342 ns, differing from the multiexponential characteristics of previously reported CsBr:Eu 2+ crystals, powders, and transparent ceramics . According to a report by Zorenko et al, a 342 ns lifetime corresponds to the radiative 4f 6 5d 1 ‐4f 7 transitions of Eu 2+ ion in Eu 2+ ‐V Cs isolated dipole centers .…”

Section: Resultsmentioning

confidence: 91%

Bright Blue Light‐Emitting Doped Cesium Bromide Nanocrystals: Alternatives of Lead‐Free Perovskite Nanocrystals for White LEDs

Yang

Zhao

Liu

et al. 2019

Advanced Optical Materials

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A X B X t r r r r ), where r A , r B , and r X stand for the ionic radii of A, B, and X, respectively. For cubic or pseudo-cubic crystal structures, the ideal value for t is 1 or a wave between 0.813 and 1.107; tolerance values that deviate significantly from 1 lead to warping and destruction of the structure. [25,26] As reported by Shannon, [27] the ionic radii for Pb 2+ and Eu 2+ are 1.19 and 1.17 Å, respectively. The similarity in size between lead and europium suggests the potential to replace lead with the more environmental-friendly europium. In this vein, many CsEuX n (X = Cl, I) structures have been reported, including CsEuCl 3 , [28,29] CsEu 2 I 5 , [30] and CsEuI 3 . [30,31] Preparation Lead-based perovskite nanocrystals (NCs) are promising candidates for use in lighting and display applications; however, the toxicity of lead is one critical issue that needs to be solved for its commercialization. Consequently, less toxic tin and bismuth-based perovskite NCs have been developed, but these materials exhibit low photoluminescence quantum yields (PLQYs) and large full width at half maximum (FWHM) values. Due to their similarity in size for Eu 2+ and Pb 2+ , the more environmental-friendly europium shows the potential to replace lead. Herein, the synthesis of Eu 2+ doped CsBr NCs with an average size of 51.5 nm via a facile hot-injection method is reported. The prepared CsBr:Eu 2+ NCs exhibit an emission peak at 440 nm with an FWHM of 31 nm and PLQY up to 32.8%, which is persistent for at least 60 d. Moreover, the size and FWHM of CsBr:Eu 2+ NCs can be tuned to 18.9 and 29 nm, respectively, by co-doping of Ca 2+ ions into the NCs. It is also demonstrated that the prepared CsBr:Eu 2+ NCs can be employed as efficient color conversion materials for fabricating white light-emitting diodes.

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Section: Resultsmentioning

confidence: 91%

Bright Blue Light‐Emitting Doped Cesium Bromide Nanocrystals: Alternatives of Lead‐Free Perovskite Nanocrystals for White LEDs

Yang

Zhao

Liu

et al. 2019

Advanced Optical Materials

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“…The emission spectra of NC-10 possess identical shape and position when excited by 272, 346, and 360 nm UV light, showing an excitation-independent nature (see Figure e). According to previous reports, these emission peaks can be assigned to the 4f 6 5d 1 –4f 7 transition of Eu 2+ in the Eu 2+ -V Cs dipole. ,− Two excitation peaks correspond to the splitting of 5d orbitals of Eu 2+ into the two components t 2g and e g , which is caused by the influence of the crystal field on the Eu 5d electrons. The peak located at 272 nm is attributed to the 4f 7 –4f 6 5d 1 (t 2g ) transitions, and to the 4f 7 –4f 6 5d 1 (e g ) transitions for the peak at 346 nm .…”

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confidence: 66%

“…The lifetime of a few hundred nanoseconds can be assigned to the radiative recombination of localized exciton in the Eu 2+ -V Cs dipole. 31,32,42 S2) showed continuous prolongation as the reaction extended. We monitored the PL decay curves of NC-10 at 430, 450, and 470 nm, respectively (see Figure S20).…”

mentioning

confidence: 97%

“…Europium-based metal halides, such as CsEuCl 3 , CsCl:Eu, , CsEuBr 3 , and CsBr:Eu, ,, are promising candidates for LHPs due to their high PLQY and narrow fwhm that are no more than 30 nm. However, most of the europium metal halides are fabricated via solid-state methods, because strong coordination between europium ions and solvent molecules hinders the formation of europium-based metal halides in solution .…”

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confidence: 99%

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Bright Blue Emission Lead-Free Halides with Narrow Bandwidth Enabled by Oversaturated Europium Doping

Qing,

Han,

et al. 2024

J. Phys. Chem. Lett.

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Eu 2+ -based lead-free metal halide nanocrystals (LFMH NCs), including CsEuCl 3 NCs and CsX:Eu 2+ NCs (X = Cl or Br), exhibit highly efficient narrow-band blue photoluminescence, making them competitive candidates for next-generation lighting and displays. However, the growing mechanism of the aforementioned NCs lacks in-depth study, which hinders the development of Eu 2+ -based nanomaterials. Herein, we demonstrate the colloidal synthesis of CsBr:Eu 2+ NCs based on an air-stable europium source. The NCs show deep blue photoluminescence centered at 444 nm, with a maximum photoluminescence quantum yield (PLQY) reaching 53.4% and a fwhm of 30 nm. We further reveal the mechanism that determines CsBr host growth and Eu 2+ doping in CsBr:Eu 2+ nanocrystals, especially dopant trapping and self-purification, that determine the PLQY level. Pure white, warm white, and cold white LEDs are fabricated based on CsBr:Eu 2+ NCs, red and green phosphors, and their performance suits the needs of highquality lighting.

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“…Eu 2+ doped phosphors usually show strong broad band emission with a short decay time, so they have been widely investigated in recent years [1][2][3][4][5][6][7][8][9][10]. The wavelength positions of the emission bands depend very much on the hosts, changing from the near-UV to the red.…”

Section: Introductionmentioning

confidence: 99%

Luminescence of YAl3 (BO3)4: Eu2+, Dy3+ phosphor and its luminescence decay characteristics

Yang

Chen

et al. 2009

J Electroceram

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Eu 2+ , Dy 3+ co-doped YAl 3 (BO 3 ) 4 phosphors are synthesized by sol-gel method. The phosphors show prominent blue luminescence due to the 4f 7 -4f 6 5d transition of Eu 2+ . The emission intensity is greatly improved when Dy 3+ is doped into the YAl 3 (BO 3 ) 4 :Eu 2+ system. The 1% Dy 3+ in Eu 2+ , Dy 3+ co-doped YAl 3 (BO 3 ) 4 phosphors is the optimum doping concentration. The luminescence decay characteristics of the samples have also been investigated, exhibiting the decay times of approximately 0.1 μs, which is much shorter compare to other Eu 2+ doped phosphors.

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Energy transfer between the Eu2+ dipole and aggregate centers in CsBr:Eu crystals

Cited by 13 publications

References 11 publications

Bright Blue Light‐Emitting Doped Cesium Bromide Nanocrystals: Alternatives of Lead‐Free Perovskite Nanocrystals for White LEDs

Bright Blue Light‐Emitting Doped Cesium Bromide Nanocrystals: Alternatives of Lead‐Free Perovskite Nanocrystals for White LEDs

Bright Blue Emission Lead-Free Halides with Narrow Bandwidth Enabled by Oversaturated Europium Doping

Luminescence of YAl3 (BO3)4: Eu2+, Dy3+ phosphor and its luminescence decay characteristics

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