Room temperature long afterglow from boron oxide: A boric acid calcined product

Zhou, Zhishan; Jiang, Kaifan; Chen, Niandi; Xie, Z.J.; Lei, Bingfu; Zhuang, Jianle; Zhang, Xuejie; Liu, Yingliang; Hu, Chaofan

doi:10.1016/j.matlet.2020.128226

Cited by 15 publications

(13 citation statements)

References 13 publications

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“…Considering the release of a large volume of reducing gases (i.e., CO and NH 3 ) during the combustion synthesis, anion vacancy (i.e., oxygen vacancy) is the most favorable defect, whilst cation vacancy is the second most favorable defect in undoped SrAl 2 O 4 . As documented in the literature, oxygen vacancy related emissions are reported for a number of host materials, among which include CaAl 2 O 4 [17,18,28], SrAl 2 O 4 [3,4,10,11], BaAl 2 O 4 [36], SrSO 4 [18,25], HfO 2 [13], Mg 2 SnO 4 [14], ZnWO 4 [30,37], and ZnMoO 4 [38]. In the case of SrAl 2 O 4 , Kamada et al reported that the broad PL spectrum of undoped SrAl 2 O 4 is comprised of 3 subbands peaking at 250, 360, and 490 nm when excited at 180 nm (6.9 eV) [33], Nazarov et al reported that the broad PL spectrum of undoped SrAl 2 O 4 consists of 4 subbands peaking at 250, 375, 450, and 520 nm when excited at 8 eV [39].…”

Section: Steady-state Pl Spectrum Of Undoped Sral 2 Omentioning

confidence: 91%

“…After intensive studies over the past 25 years, it is widely accepted that Eu 2+ is the luminescent center of the afterglow for Eu 2+ and Re 3+ codoped SrAl 2 O 4 phosphors [1,2,[7][8][9]. However, this belief has recently been challenged by the following facts: (i) green afterglows peaking at about 520 nm are observed in Dy 3+ doped SrAl 2 O 4 and in Tb 3+ doped SrAl 2 O 4 [3,4,10,11] [12]; and (iii) blue and blue-green afterglows are recorded in a variety of undoped materials, among which include HfO 2 [13], Mg 2 SnO 4 [14], CaAl 2 O 4 [15,16], boric oxide [17], and SrSO 4 [18]. These challenging facts suggest that the native defects in SrAl 2 O 4 , namely the oxygen and strontium vacancies, are likely to be the origin of the afterglow.…”

Section: Introductionmentioning

confidence: 99%

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Green Afterglow of Undoped SrAl2O4

Zhai

Huang

2021

Nanomaterials

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Undoped SrAl2O4 nanocrystals were obtained via solution combustion using urea as fuel. The afterglow properties of undoped SrAl2O4 were investigated. Green afterglow from undoped SrAl2O4 is visible to the human eye when the 325 nm irradiation of a helium–cadmium laser (13 mW) is ceased. The afterglow spectrum of undoped SrAl2O4 is peaked at about 520 nm. From the peak temperature (321 K) of the broad thermoluminescence glow curve, the trap depth of trap levels in undoped SrAl2O4 is estimated to be 0.642 eV using Urbach’s formula. Based on first-principles density functional calculations, the bandstructures and densities of states are derived for oxygen-deficient SrAl2O4 and strontium-deficient SrAl2O4, respectively. Our results demonstrate that the green afterglow of undoped SrAl2O4 originates from the midgap states introduced by oxygen and strontium vacancies. The observation of green afterglow from undoped SrAl2O4 helps in gaining new insight in exploring the afterglow mechanisms of SrAl2O4-based afterglow materials.

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Section: Steady-state Pl Spectrum Of Undoped Sral 2 Omentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Green Afterglow of Undoped SrAl2O4

Zhai

Huang

2021

Nanomaterials

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“…It is proved that the RTP of B 2 O 3 originates from its structural defects in our previously published work. [14] In addition, the formation of boron carbon bonds (covalent bonds) between CDs and B 2 O 3 may further influent the lifetime of the afterglow. [6] To confirm the energy level diagram of P-CDs@B 2 O 3 , afterglow features were further investigated.…”

Section: Resultsmentioning

confidence: 99%

“…[13] Our previous work reported activated multicolor RTP of CDs in boron oxide (B 2 O 3 ) matrix and blue afterglow emission of B 2 O 3 generated from oxygen traps. [6,14] Gogoi et al reported green phosphorescence associated with triplet excitons in urea heated product. [15] Inspired by the donor-acceptor emission mechanism, we try to construct a system based on EnT through encapsulating nonmatrix phosphorescent CDs in afterglow matrixes to prepare CDs exhibiting long RTP.…”

Section: Introductionmentioning

confidence: 99%

Energy Transfer Mediated Enhancement of Room‐Temperature Phosphorescence of Carbon Dots Embedded in Matrixes

Zhou

Song

Liu

et al. 2021

Advanced Optical Materials

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Energy transfer (EnT) is a commonly used study method in the research of organic luminescent materials, but rarely reported in carbon dots (CDs) related work. In this work, an efficient EnT mediated method for enhancing room temperature phosphorescence (RTP) of CDs through embedding pure phosphorescent CDs into afterglow matrixes is brought up for the first time. In such design system, the emission intensity, phosphorescence lifetime, and emission time of CDs are prolonged significantly, and all the CD‐based materials emit more than 20 s phosphorescence visible to eye after the ultraviolet excitation. The overlap between the phosphorescence excitation spectra of CDs and the afterglow emission spectra of afterglow matrixes reveal the possibility of the EnT from matrixes to CDs, and the phosphorescence emission and lifetimes spectra of CDs, matrixes, and CDs@matrix further verify the presence of EnT process. Besides, phosphorescent CDs embedded in nonafterglow emission matrixes are also synthesized for analysis and comparison. To employ the outstanding characteristics of the compound of pure phosphorescent CDs and afterglow matrix, advanced information encryption/decryption and rapid fingerprint detection applications are designed. This EnT medicated enhancing RTP strategy provides a new design route to construct the CD‐based material with long phosphorescence emission and high emission intensity.

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“… 11 Moreover, Zhou et al recently reported blue afterglow from undoped boron oxide. 26 Thus, the knowledge on defect energy levels of intrinsic defects, particularly the oxygen and strontium vacancies, in SrSO 4 can help in understanding the origin of cyan afterglow of SrSO 4 .…”

Section: Results and Discussionmentioning

confidence: 99%

Blue Photoluminescence and Cyan-Colored Afterglow of Undoped SrSO₄ Nanoplates

Zhai

Zhang

et al. 2021

ACS Omega

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Undoped SrSO 4 nanoplates were synthesized via the composite hydroxide-mediated approach. The products were characterized by means of X-ray diffractometry, scanning electron microscopy, X-ray energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, photoluminescence (PL) spectroscopy, electron spin resonance technique, afterglow spectroscopy, and thermoluminescence dosimetry. The steady-state PL spectrum of undoped SrSO 4 nanoplates can be deconvoluted into two distinct Gaussian bands centered at 2.97 eV (417.2 nm) and 2.56 eV (484.4 nm), respectively. The nature of the defect emissions is confirmed through the emission-wavelength-dependent PL decays as well as the excitation-wavelength-dependent PL decays. A cyan-colored afterglow from undoped SrSO 4 nanoplates can be observed with naked eyes in the dark, and the afterglow spectrum of the undoped SrSO 4 nanoplates exhibits a peak at about 492 nm (2.52 eV). The duration of the afterglow is measured to be 16 s. The thermoluminescence glow curve of the undoped SrSO 4 nanoplates shows a peak at about 40.1 °C. The trapping parameters are determined with the peak shape method, the calculated value of the trap depth is 0.918 eV, and the frequency factor is 1.2 × 10 14 s –1 . Using density functional calculations, the band structures and densities of states of oxygen-deficient SrSO 4 and strontium-deficient SrSO 4 are presented. The mechanisms of the cyan-colored afterglow are discussed for undoped SrSO 4 , and the oxygen vacancies in SrSO 4 are proposed to be the luminescence center of the afterglow.

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Room temperature long afterglow from boron oxide: A boric acid calcined product

Cited by 15 publications

References 13 publications

Green Afterglow of Undoped SrAl2O4

Green Afterglow of Undoped SrAl2O4

Energy Transfer Mediated Enhancement of Room‐Temperature Phosphorescence of Carbon Dots Embedded in Matrixes

Blue Photoluminescence and Cyan-Colored Afterglow of Undoped SrSO₄ Nanoplates

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Room temperature long afterglow from boron oxide: A boric acid calcined product

Cited by 15 publications

References 13 publications

Green Afterglow of Undoped SrAl2O4

Green Afterglow of Undoped SrAl2O4

Energy Transfer Mediated Enhancement of Room‐Temperature Phosphorescence of Carbon Dots Embedded in Matrixes

Blue Photoluminescence and Cyan-Colored Afterglow of Undoped SrSO4 Nanoplates

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Blue Photoluminescence and Cyan-Colored Afterglow of Undoped SrSO₄ Nanoplates