Trap depth optimization to improve optical properties of diopside-based nanophosphors for medical imaging

Maldiney, Thomas; Lecointre, Aurélie; Viana, Bruno; Bessière, Aurélie; Gourier, Didier; Bessodes, Michel; Richard, Cyrille; Scherman, Daniel

doi:10.1117/12.909865

Cited by 21 publications

(15 citation statements)

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“…Second, thermoluminescence (TL) measurement was carried out and the result is displayed in Figure b. Two intense TL peaks (denoted as traps A and B) were observed peaking at 283 and 407 K, and the trap depths ( E trap (A) and E trap (B)) are estimated to be ≈0.57 and ≈0.81 eV, respectively, by using the relationship E trap = T /500 (eV), where the temperature T is in units of K . These defect levels are supposed to originate from intrinsic oxygen vacancies from the consideration that the materials were synthesized in reducing atmosphere and contain seven symmetrically distinct oxygen sites.…”

Section: Resultsmentioning

confidence: 99%

Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇

Shi

Ning

Wang

et al. 2019

Advanced Optical Materials

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Mn2+‐activated phosphors usually show green to red luminescence depending on the crystal field strength in the lattice. However, the severe intensity loss of Mn2+ luminescence at elevated temperatures remains to be a serious problem. Here, the observation of zero‐thermal quenching of Mn2+ red luminescence (λem = 620 nm) up to 500 K in Eu2+, Mn2+‐codoped BaMgP2O7 is reported. This phenomenon arises from an efficient energy transfer from sensitizers Eu2+ which, when singly doped, exhibits a substantial thermal‐induced enhancement of 5d→4f emission intensity at 400 nm, along with a high luminescence efficiency and a large UV light absorption capacity. The present results open up a new path to the exploration of Eu2+, Mn2+‐codoped materials for thermally stable red phosphors.

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Section: Resultsmentioning

confidence: 99%

Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇

Shi

Ning

Wang

et al. 2019

Advanced Optical Materials

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“…Interestingly, we reveal that, introducing V P , V PO3 (simultaneous formation of one P and one O3 vacancy in one [PO 4 ] unit), V PO3,1 , and V PO1‐4 (one P and four O vacancies in one [PO 4 ] unit) causes the occurrence of a series of shallow trap levels near the conduction and/or valence bands. We point out that the suitable trap depth for room temperature afterglow is around 0.6 eV with respect to the conduction or valence band . Although the DFT method used here underestimate the bandgap, the presence of a series of charge‐transition levels of different defect states leads us to hypothesize that these defects in LaPO 4 could act as trap centers for afterglow.…”

Section: Resultsmentioning

confidence: 82%

Theory‐Guided Defect Tuning through Topochemical Reactions for Accelerated Discovery of UVC Persistent Phosphors

Hong

Liu

et al. 2019

Advanced Optical Materials

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Long persistent phosphors (LPPs) have attracted enduring attention owing to their wide applications. However, the discovery of LPPs is thus far largely the results of trial and error. Here, theory‐guided defect tuning through topochemical reactions is demonstrated for accelerated discovery of emerging LPPs. First‐principles calculations are employed to identify the thermodynamic charge‐transition levels of different defect states, which help examine whether the candidate structure is a suitable host for afterglow. Rationally tuning the species and concentrations of defects through topochemical reactions is then illustrated, which leads to discovery of Pr3+‐doped LaPO4 featuring ultraviolet C afterglow with a lasting time of over 2 h. Such a strategy, in conjunction with advanced characterizations including high‐resolution synchrotron X‐ray diffraction, positron annihilation lifetime spectroscopy, and electron spin resonance, suggests a radical‐involved afterglow mechanism. Importantly, it is illustrated that this concept can be extended for the discovery of more LPPs. It is suggested that theory‐guided defect engineering enabled by topochemical reactions can be used as a powerful tool to accelerate discovery of novel LPPs with much clearer afterglow mechanisms, with implications even for the design of other optoelectronic materials.

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“…As could be seen on Figure 7, by working on the chemical composition of the silicate, the authors were able to increase by a factor 5 the intensity of luminescence in vivo , allowing to perform imaging for longer time 58,59,60,61.…”

Section: The First Generation Of Plnps For Bioimaging: Matrix Silicatementioning

confidence: 99%

Chemically engineered persistent luminescence nanoprobes for bioimaging

L’Ecuyer¹,

Teston²,

et al. 2016

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Imaging nanoprobes are a group of nanosized agents developed for providing improved contrast for bioimaging. Among various imaging probes, optical sensors capable of following biological events or progresses at the cellular and molecular levels are actually actively developed for early detection, accurate diagnosis, and monitoring of the treatment of diseases. The optical activities of nanoprobes can be tuned on demand by chemists by engineering their composition, size and surface nature. This review will focus on researches devoted to the conception of nanoprobes with particular optical properties, called persistent luminescence, and their use as new powerful bioimaging agents in preclinical assays.

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Trap depth optimization to improve optical properties of diopside-based nanophosphors for medical imaging

Cited by 21 publications

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Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇

Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇

Theory‐Guided Defect Tuning through Topochemical Reactions for Accelerated Discovery of UVC Persistent Phosphors

Chemically engineered persistent luminescence nanoprobes for bioimaging

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Trap depth optimization to improve optical properties of diopside-based nanophosphors for medical imaging

Cited by 21 publications

References 0 publications

Zero‐Thermal Quenching of Mn2+ Red Luminescence via Efficient Energy Transfer from Eu2+ in BaMgP2O7

Zero‐Thermal Quenching of Mn2+ Red Luminescence via Efficient Energy Transfer from Eu2+ in BaMgP2O7

Theory‐Guided Defect Tuning through Topochemical Reactions for Accelerated Discovery of UVC Persistent Phosphors

Chemically engineered persistent luminescence nanoprobes for bioimaging

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Product

Resources

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Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇

Zero‐Thermal Quenching of Mn²⁺ Red Luminescence via Efficient Energy Transfer from Eu²⁺ in BaMgP₂O₇