ACS Applied Electronic Materials
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2021
·
IF 3.314
Junqing Xiahou,Qi Zhu,Lin Zhu,Siyuan Li,Ji-Guang Li
Modern engineering fields put forward requirements for optical temperature sensors, which need natural-light excitation/storage and near-infrared (NIR) afterglow emission for some special conditions. Here, NIR persistent luminescent phosphors of ZnGa2–x(Mg/Ge)xO4:Cr3+ (x = 0–1.25) have been synthesized. The incorporation of Mg2+/Ge4+ ions in ZnGa2O4:Cr3+ resulted in more defect clusters of “MgGa′–GeGa•” and “ZnGa′–GeGa•” and interstitial oxygens (OInt). Increasing the calcination temperature and Mg2+/Ge4+ doping both contributed to the generation of OInt. Higher efficiency of visible light excitation was observed, mainly due to the defect clusters and OInt. The samples exhibited a bright NIR emission at 695 nm by exposure to UV or visible light, and the NIR signal can last longer than 1 h after the stoppage of excitation. Incorporation of Mg2+/Ge4+ and increasing the calcination temperature both resulted in a deeper trap depth. However, the density of trapped charge carriers takes the dominant role in the persistent luminescence. Therefore, the x = 0.25 sample, having the most trapped charge carriers, exhibits the best afterglow performance. The prepared phosphor exhibited a temperature-dependent persistent luminescence behavior, which can charge natural light and release NIR light repeatedly many times, indicating that they are the potential natural-light rechargeable materials for temperature sensing.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Wenfei Qin,Peng Zhang,Xuan Miao,Yuzhu Yang,Sixia Li,Sai Zhou,Weisheng Liu
Self-activated near-infrared (NIR) phosphors have recently gained extensive attention in special illumination and biomedical applications owing to its non-toxicity, inexpensiveness and especially undoped luminescence center ions. However, high photoluminescence quantum yields (PLQY) and thermal stability remain challenges for NIR-emitting phosphors. In this study, a self-activated phosphor Ca 3 La 2 W 2 O 12 (CLWO) successfully achieved a NIR emission and high thermal stability. Under 350 nm excitation, the optimal CLWO:0.2 %Bi 3+ phosphor shows a narrowband emission in the range of 650–800 nm and a full width of half maximum (FWHM) of 36 nm. Mechanism studies demonstrate that the interstitial oxygen within CLWO host can work as the luminescence center, and enables self-activated emission in NIR waveband. Moreover, CLWO:0.2 %Bi 3+ phosphor shows a high PLQY of 48.84 % and excellent thermal stability (I 420 K /I 300 K = 69.09 %). A NIR phosphor-converted LED (pc-LED) based on a Ca 3 La 2 W 2 O 12 :Bi 3+ (CLWO:Bi 3+ ) phosphor is fabricated on a 350 nm LED chip, demonstrating its potential in NIR night-vision monitoring. This work certainly designs novel insights for outstanding thermal stability of self-activated phosphors and develops new research avenues for self-activated NIR LED light sources applications.
研究领域:
材料科学
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光学
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生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2024
·
IF 3.3
Aynigar Ablat,Min Yin,Shihang Zhou,Aierken Sidike
Ce 3+ -doped Ca 2 BO 3 Cl and Ca 3 (BO 3 ) 2 are presented as promising phosphors for solid-state white light illumination, display, phototherapy, etc. Herein, we combined experimental and first-principles calculations to study the photoluminescence properties of Ce 3+ -doped Ca 2 BO 3 Cl and Ca 3 (BO 3 ) 2 under different preparation environment. The results show that the co-doped Na + ions have little effect on the luminescence of Ce 3+ ions doped Ca 2 BO 3 Cl and Ca 3 (BO 3 ) 2 . However, the luminous intensity of Ce 3+ /Na + ions co-doped Ca 2 BO 3 Cl greatly decreased with increasing oxidizing atmosphere. When sintering at 800 °C in air, the luminescence intensity was more than 10 times lower than that in a reducing atmosphere (5 % H 2 + 95 % N 2 ), whereas the luminescence intensity of Ce 3+ -doped Ca 3 (BO 3 ) 2 hardly changed. First-principles calculations revealed that, within an enhanced oxidizing atmosphere, the formation energy of interstitial oxygen (O i ) in Ca 2 BO 3 Cl:Ce 3+ ,Na + decreased from 2.84 to 0.31 eV, whereas in Ca 3 (BO 3 ) 2 :Ce 3+ , it decreased from 2.11 to 1.51 eV. The small formation energy (0.31 eV) of interstitial oxygen (O i ) in an oxidation atmosphere may lead to the formation of interstitial oxygen defects in Ca 2 BO 3 Cl:Ce 3+ ,Na + , which may result in the luminescence quenching of Ce 3+ ions in Ca 2 BO 3 Cl:Ce 3+ ,Na + ((Ce 3+ )∗+O 0 →Ce 4+ +O 1− ) and cause a decrease in the luminescence intensity. The study of the difference in resistance to oxidation between Ce 3+ -doped Ca 2 BO 3 Cl and Ca 3 (BO 3 ) 2 is highly important for further improving current luminescent materials and developing new functional materials.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2020
·Vol. 22
·期 17
·9362-9367
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IF 3.43
Weifeng Huang,Yingcai Zhu,Yong Liu,Lijuan Liu,Changchun Yang,Wei Xu
The quaternary chalcogenides consisting of earth-abundant elements such as Cu2ZnSnSe4 (CZTSe) have promising electrical and optical properties prompting enormous technological interest. Understanding different types of defects including Cu/Zn ordering is believed to be the key point to tackle technological challenges such as a large open circuit voltage deficit in CZTSe. The Te doped Cu2.2Zn0.8SnSe4−xTex (x = 0.01–0.04) were investigated using X-ray absorption fine structure spectroscopy at the Cu, Zn, and Se K-edges as well as at the Te L3-edge. Cu at the zinc site with anti-site defects and oxygen interstitials are identified. The detailed electronic structure upon Te doping is studied, providing insights into the rich defect chemistry present in this compound.
研究领域:
材料科学
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凝聚态物理
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无机化学
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半导体材料
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光电功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）