JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xin Li,Xusheng Wang,Rui Hu,Yanxia Li,Xi Yao
We report a novel mechanoluminescent phosphor Li 1−x Ca x Si x Ta 1−x O 3 :0.01Pr 3+ (x = 0–0.04). The crystal structure, photoluminescence (PL), optical diffuse reflectance spectra, afterglow (AG), fluorescence decay curves, and mechanoluminescence (ML) properties were investigated. To clarify the defect types and the mechanoluminescence mechanisms, an X-ray photoelectron spectroscopy (XPS) and thermoluminescence curve (TL) were measured. The dopants Ca 2+ and Si 4+ ions occupied the Li+ and Ta 5+ sites, respectively. An optimal sample Li 0.98 Ca 0.02 Si 0.02 Ta 0.98 O 3 :Pr 3+ was obtained with great enhancement in mechanoluminescence intensity, higher than that of non-doped sample LiTaO 3 :Pr 3+ by 262%. And the compression threshold, over which the ML intensity could not maintain the linear increase, has also been greatly improved. Furthermore, the stable output of Tribo-L was achieved, which was visible to the naked eye. A probable mechanism was proposed to illustrate the mechanoluminescent process in Li1-xCaxSixTa1-xO3:0.01Pr3 + (x = 0–0.04). The study indicates that adjusting trap distribution by substituting host ions may be a novel way to develop high-quality mechanoluminescence.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Materials
·
2023
·Vol. 17
·期 1
·59
·
IF 3.4
Jia-Xuan Wang,Yong-Gang Chen,Ji-Ming Chen,Zhi-Hui Yin,Chun-Song Chen,Yi-Fei Li,Ting Deng,Xiao-Bo Guo,Ming-Xiao Zhu
Polymeric dielectrics exhibit remarkable dielectric characteristics and wide applicability, rendering them extensively employed within the domain of electrical insulation. Nevertheless, the electrical strength has always been a bottleneck, preventing its further utilization. Nanocomposite materials can effectively improve insulation strength, but uniform doping of nanofillers in engineering applications is a challenge. Consequently, a nanocomposite interfacial coating was meticulously designed to interpose between the electrode and the polymer, which can significantly improve DC breakdown performance. Subsequently, the effects of filler concentration and coating duration on DC breakdown performance, high field conductivity, and trap distribution characteristics were analyzed. The results indicate that the composite coating introduces deep traps between the electrode-polymer interface, which enhances the carrier confinement, resulting in reduced conductivity and enhanced DC breakdown strength. The incorporation of a composite coating at the interface between the electrode and polymer presents novel avenues for enhancing the dielectric insulation of polymers.Keywords:breakdown strength;conduction current;trap distribution;surface coating;spraying
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Ying Lv,Wuqiang Li,Chaofeng Li,Yu Liu,Cunjian Lin,Zhongyuan Li,Shihai You
The commercial blue persistent luminescent (PersL) phosphor (CaAl2O4:Eu2+,Nd3+) is renowned for its exceptional PersL duration, but it is hampered by its poor chemical stability. There is an urgent need to develop blue PersL phosphors that can combine the excellent PersL property with robust stability. In this work, we report on a series of highly stable Ce3+-doped oxynitride PersL phosphors. Notably, BaSi3Al3O4N5:Ce3+ has been identified to contain two distinct types of defects in the host: one associated with photoluminescence (PL) and the other with electron trapping and detrapping dynamics. These intrinsic defects have been systematically investigated and confirmed by analyzing both PL and PersL spectra, which could be generated by nitrogen deficiency and the existing oxygen vacancy in BaSi3Al3O4N5. BaSi3Al3O4N5:Ce3+ has a widely distributed trap from 0.21 to 1.02 eV, with a peak at 0.63 eV, as determined by the initial rise method. BaSi3Al3O4N5:Ce3+ exhibits not only excellent water-resistance stability but also superior heat-resistant stability. Leveraging its widely distributed traps and great chemical stability, we have successfully demonstrated the optical information storage ability of BaSi3Al3O4N5:Ce3+ by using a gradual optical writing method. This comprehensive study provides valuable insights into the development of stable oxynitride PersL phosphors for potential applications in optoelectronic devices.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2012
·
IF 2.421
Z.L. Zhang,M. Wan,Y.L. Mao
A TiO 2 -based composite, ZnFe 2 O 4 /TiO 2 , was prepared with a commercial TiO 2 (Degussa P25) and ZnFe 2 O 4 nanopowders using a simple method. The composite was characterized by X-ray diffraction (XRD), UV–vis absorption spectrum, surface photovoltage spectroscopy (SPS) and SEM. The composite presents an enhanced photovoltaic effect compared with the pure TiO 2 . The trap distributions of TiO 2 and ZnFe 2 O 4 /TiO 2 composite were investigated and the energy levels of TiO 2 and ZnFe 2 O 4 were analyzed. The results indicate that the enhancement of photovoltaic effect is mainly due to the increase of photo-generated carrier concentration and improvement of the separation efficiency of photo-generated carriers by the addition of ZnFe 2 O 4 .
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Cong He,Bing Li,Chunwen Ye,Meng Wu,Yanjie Zhang
Multi-modal strategies for optical information storage have received a lot of attention to meet the increasing security requirements. In this case, long persistent luminescence (LPL) phosphors with different dopant ions were obtained by introducing Dy 3+ and Ho 3+ ions into the BaSi 2 O 5 :Eu 2+ phosphor to adjust the distribution and depth of the trap centers. The generation of the pure phase BaSi 2 O 5 was confirmed by X-ray diffraction (XRD) and XRD Rietveld refinement . The peak emission of BaSi 2 O 5 : Eu 2+ phosphor is about 500 nm with 313 nm excitation. Both BaSi 2 O 5 : Eu 2+ , Dy 3+ , and BaSi 2 O 5 : Eu 2+ , Ho 3+ phosphors exhibit emission characteristics of Eu 2+ ions. The trap depths of the three phosphors are different by Gaussian fitting of thermoluminescence (TL) curves, and the depth of BaSi 2 O 5 : Eu 2+ , Dy 3+ phosphor can reach 1.070 eV. Typically, the flexible luminescent film based on BaSi 2 O 5 : Eu 2+ phosphor can be written optical pattern using 365 nm ultraviolet (UV) light, such as "DL" and "fireworks" patterns, and subsequently read out by thermal or infrared light stimulus. Further, a strategy for encryption and decryption of dynamic optical information in Morse code has been developed using BaSi 2 O 5 : Eu 2+ , BaSi 2 O 5 : Eu 2+ , Dy 3+ , and BaSi 2 O 5 : Eu 2+ , Ho 3+ phosphors, indicating the prospective use in optical information security.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Ying Lv,Ning Zhao,Wuqiang Li,Cunjian Lin,Changjian Chen,Jumpei Ueda
Persistent phosphors are widely investigated in indications, bio-imaging, information storage, and anticounterfeiting. However, it remains a challenge to develop highly stable persistent phosphors with abundant and widely distributed traps. Here, a Ba 0.58 Sr 0.4 Al 3 Si 3 O 4 N 5 :0.02Yb 2+ (Ba 0.6 Sr 0.4 Al 3 Si 3 O 4 N 5 :Yb 2+ ) persistent phosphor with an excellent persistent luminescence (PersL) time of 383 min is reported before decaying to 0.32 mcd m −2 due to the existence of abundant intrinsic electron traps. Ba 0.6 Sr 0.4 Al 3 Si 3 O 4 N 5 :Yb 2+ owns a trap distribution ranging from 0.41 to 1.04 eV and has a remarkably broad full width at half maximum (FWHM) of TL curve (169 K) among currently reported persistent phosphors. The robust stability of Ba 0.6 Sr 0.4 Al 3 Si 3 O 4 N 5 :Yb 2+ is evidenced by immersing in hot water and annealing at the high temperature for different time, which showed PersL retention rates of over 90%. Temperature-assisted information storage in this persistent phosphor is successfully demonstrated. Furthermore, a step-by-step write-in method is implemented in anticounterfeiting, and the coded information can be optionally decoded at different temperatures due to the wide trap distribution in Ba 0.6 Sr 0.4 Al 3 Si 3 O 4 N 5 :Yb 2+ . This work demonstrates highly stable oxynitride persistent phosphors with widely distributed traps show great promise in information storage, anticounterfeiting, and photodetectors.
研究领域:
材料科学
·
光学
·
信息科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 9
·2200
·
IF 5.076
Jun Xie,Chaoxuan Xiao,Shuai Shao,Qijun Duan,Qing Xie,Fangcheng Lü
In the direct current electric field, the surface of epoxy resin (EP) insulating material is prone to charge accumulation, which leads to electric field distortion and damages the overall insulation of the equipment. Nano-doping is an effective method to improve the surface insulation strength and DC flashover voltage of epoxy resin composites. In this study, pure bismuth ferrite nanoparticles (BFO), as well as BFO nanofillers, which were doped by La element, Cr element as well as co-doped by La + Cr element, were prepared by the sol-gel method. Epoxy composites with various filler concentrations were prepared by blending nano-fillers with epoxy resin. The morphology and crystal structure of the filler were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests. The effects of different filler types and filler mass fraction on the surface flashover voltage, charge dissipation rate, and trap characteristics of epoxy resin composites were studied. The results showed that element doping with bismuth ferrite nanofillers could further increase the flash voltage of the composites. The flashover voltage of La + Cr elements co-doped composites with the filler mass fraction of 4 wt% was 45.2% higher than that of pure epoxy resin. Through data comparison, it is found that the surface charge dissipation rate is not the only determinant of the flashover voltage. Appropriately reducing the surface charge dissipation rate of epoxy resin composites can increase the flashover voltage. Finally, combining with the distribution characteristics of the traps on the surface of the materials to explain the mechanism, it is found that the doping of La element and Cr element can increase the energy level depth and density of the deep traps of the composite materials, which can effectively improve the flashover voltage along the surface of the epoxy resin.Keywords:bismuth ferrite nanoparticles;epoxy resin;DC flashover voltage;surface charge;trap distribution
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2022
·Vol. 14
·期 17
·3605
·
IF 4.967
Jiang Wu,Bo Zhang,Tianjiao Li,Yan Du,Wen Cao,Hao Yang
The operating safety of spacecraft in space environments is closely related to the surface discharging phenomenon of dielectrics such as polyimide (PI) film in solar arrays; moreover, carrier traps in the dielectric can affect its insulation performance. Therefore, to improve the vacuum surface flashover characteristics of PI film by nano modification and reveal the effect of trap distribution on the flashover of PI composite film, first, the original PI and nano-ZnO/PI composite films with different additive amounts (0.5, 1, 2, and 3 wt.%) were prepared by in situ polymerization and their performance was evaluated by the physicochemical properties characterized by methods such as thermogravimetric analysis; second, the surface traps of the original and nanocomposite films were measured and calculated by surface potential decay method, and the carrier mobility was also obtained; finally, the vacuum direct current (DC) surface flashover characteristics and bulk resistivity of all the film samples were measured and analyzed. The experiment results showed that with the increase in the amount of nano-ZnO, both the shallow and deep trap density increased significantly, while the trap energy varied slightly, and the surface flashover voltage also increased obviously. Based on the multi-core model, the increases in the shallow and deep trap density after the introduction of nano-ZnO into the PI matrix was analyzed from the microscopic perspective of the interface. Based on the comparative analysis of the trap distribution and surface flashover voltage characteristics, a bilayer model of vacuum DC surface flashover development was proposed. In the bilayer model, deep traps and shallow traps play a dominant role in the vacuum–solid interface and the inner surface of the dielectric, respectively, and increasing the trap density could effectively inhibit secondary electron multiplication on the surface and accelerate charge dissipation inside the film. Consequently, nano-ZnO can purposefully control the trap distribution, and then improve the flashover characteristics of nano-ZnO/PI composite films, which provides a new approach for improving the spacecraft material safety.Keywords:nanocomposite;polyimide film;trap distribution;DC surface flashover;bilayer model
研究领域:
材料科学
·
航天工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Dedan Mu,Tianchi Wang,Junheng Yuan,Lulu Han,Hao Song,Shuyi Yao,Bin Meng,Ting Wang,Xuhui Xu
X-ray detection is vital in various fields such as medical imaging, security screening, and materials analysis. However, to meet the diverse detection requirements across different scenarios, current scintillators used for X-ray detection encounter challenges in both immediate and delayed radiation detections. In this work, flexibly controlling trap distribution through extra ions doping into Cs 2 NaTbCl 6 lead-free perovskites presents a promising avenue for addressing these challenges and advancing X-ray dose detection capabilities across diverse scientific domains. By doping Sb 3+ ions into the Cs 2 NaTbCl 6 host, the traps are significantly passivated through improved crystallinity, resulting in the suppression of afterglow behaviors and endowing the high-resolution real-time dynamic X-ray detection. Additionally, the incorporation of Mn 2+ into the Cs 2 NaTbCl 6 matrix causes significant lattice distortion, leading to increased concentrations of both shallow and deep traps, effectively boosting delayed X-ray detection efficiency. This work may provide an effective strategy for constructing efficient scintillators for the realization of multi-environmental X-ray imaging.
研究领域:
材料科学
·
放射学
·
医学成像
·
安全检查
·
材料分析
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 48
·18404-18414
·
IF 8.067
Shaoxing Lyu,Pengshang Zhou,Jiaren Du,Xiaomeng Wang,Tengyue Wang,Panqin Wang,Henggang Wang,Shan Sun,Hengwei Lin
Near-infrared (NIR) emitting phosphors with persistent luminescence have attracted much interest in the past decade, due to their widespread applications in medical diagnostics, night-vision surveillance, multi-level anti-counterfeiting, and security encryption. Although NIR luminescent materials have been extensively investigated, it is challenging to explore novel phosphors or new compositions with tunable NIR persistent luminescence performance. Herein, chemical unit co-substitution is explored in a series of NIR emitting Zn1−2xLixGa2+xO4:Cr3+ solid solutions. Substitution with [Li+–Ga3+] for the [Zn2+–Zn2+] unit results in tunable emission in the deep-red and NIR regions coming from the typical Cr3+ emission of the 2E → 4A2 and 4T2 → 4A2 transition. Upon UV or X-ray irradiation, intense NIR persistent luminescence is realized and composition-related variation of trap distributions and densities are identified. Importantly, a higher trap density of the Cr3+-doped solid solutions (i.e., x = 0.2–0.4) than that of the benchmark NIR persistent phosphor of ZnGa2O4:Cr3+ and LiGa5O8:Cr3+ is achieved. This work proves the feasibility of chemical unit co-substitution in developing new NIR persistent phosphors, which can motivate further exploration of luminescent materials with novel properties.
研究领域:
材料科学
·
光学
·
光子学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）