JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 15
·11625-11631
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IF 2.779
Xing Zhuo,Weng Juhai,Ma Chi
A series of Ga 3+ -doped Zn 2 GeO 4 willemite ceramics, in a general formula Zn 2+0.5 x Ge 1− x Ga x O 4 (0.1 ≤ x ≤ 0.4), were prepared and the influence of Ga 3+ doping on the phase composition, structure, microstructure, and microwave dielectric properties were studied. XRD, SEM, and Raman analysis evidence that by moderate gallium substitution in the nominal Zn 2 GeO 4 , the unfavorable ZnO phase was suppressed, while a low-loss ZnGa 2 O 4 phase was induced. With increasing doping content, the ZnGa 2 O 4 phase increases in phase percentage and becomes dominant (~ 69%) after x = 0.3. Due to the mixture rule, both relative permittivity and quality factor were improved, which is related to the superior dielectric properties of ZnGa 2 O 4 compared to Zn 2 GeO 4 . The microwave dielectric properties show a remarkable dependence on the composition. Sintered at 1230 °C, a combination of dielectric performances with ε r ~ 9.4, Q × f ~ 97,000 GHz, and τ f ~ − 30.7 ppm/°C was accessed in the x = 0.4 composition.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yanzhen Yin,Wenhua Yang,Zhen Wang,Yue Zhang,Maochen Zhu,Chao Dou,Yang Che,Shijia Sun,Chen Hu,Bing Teng,Jiaqi Zhao,Jingyao Lu,Ruyi Sun,Degao Zhong
The struggle with "thermal load" is always an unavoidable challenge for photo-luminescent material. In this work, a novel red phosphor of ZnGa 2 O 4 : Eu 3+ with spinel-type structure is prepared by high-temperature solid-phase method. Due to the charge imbalance during the replacement processes of Ga 3+ →Zn 2+ and Eu 3+ →Zn 2+ in mixed spinel structure, vacancy defects can be introduced into the lattice structure of ZnGa 2 O 4 : 0.02Eu 3+ . The results of Density Function Theory (DFT) calculation demonstrate that the existence of vacancy defects can construct defect energy levels in the energy band structure of the host crystal, which can assist enhancing the fluorescence emission intensity of the phosphor at high temperature. The strong thermal stability of its own structure combined with the assistance of defect energy levels enables the achievement of zero-thermal quenching in ZnGa 2 O 4 : 0.02Eu 3+ under multi-wavelength excitation. Our results open up a new way for the exploration and utilization of zero-thermal quenching phosphors.
研究领域:
材料科学
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发光材料
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固态化学
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计算材料学
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无机功能材料
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DOI
高影响因子
Inorganic Chemistry Frontiers
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2022
·Vol. 9
·期 8
·1802-1811
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IF 7.779
Zhi-Han Zuo,Song-Lin Jiang,Zhi-Hao Zhang,Jinhui Liang,Junhao Li,Zhao-Qing Liu,Yibo Chen
How electron traps in a host matrix impact the fluorescence intensity ratio (FIR) thermometry performance in inorganic phosphors is still unclear. In this work, relationships between temperature-dependent photoluminescence, fluorescence intensity ratio-based optical thermometry performance, and concentration of the electron traps have been thoroughly investigated in a Mn-doped ZnGa2O4 spinel system. The results reveal that the sample with a higher concentration of electron traps shows a thermometry sensitivity (Sr) of 3.47% K−1 read from the FIR of the green channel (Mn2+) and the red channel (Mn4+), which is over twice higher than that of the sample with a lower concentration of electron traps. Detailed photoluminescence, thermoluminescence, and first-principles calculations demonstrate that the performance enhancement is dominantly caused by a selective thermally induced emission compensation through the antisite defects in the ZnGa2O4 host. The defects act as electron traps and compensate for the intensity decline of the green channel by releasing electrons at high temperatures while leaving the red channel unaffected, thus increasing the FIR value and the sensitivity. This work shows a significant enhancement effect of the electron traps on the FIR thermometry performance in ZnGa2O4:Mn and provides a novel strategy for thermometry performance enhancement through the manipulation of traps.
研究领域:
材料科学
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光学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2026
·
IF 5.1
Dingjun Jia,Wenna Gao,Wenqian Xu,Xiangyu Zhang,Dangli Gao
Persistent luminescence (PersL) phenomenon is the result of dynamic distribution of microscopic charges caused by an external field stimulation. A long-standing unresolved question is that why red afterglow phosphors activated by Cr3+ can mainly be obtained in Ga-based compounds. Here, we systematically investigate the ZnGa2O4:0.5%Cr3+,0.5%M3+ (M = Bi, Tb) and ZnGa2O4:0.5%Cr3+ phosphors by a combination of experimental characterizations and first-principles calculations. An enhanced Cr3+ PersL mechanism is proposed based on the regulation of the band gap structure and the redistribution of electron clouds by doping. These changes localize the defect energy levels near the Fermi level, thereby transforming them into effective traps. Additionally, the Cr3+ doping keeps the original ZnGa2O4 rigidity, while enhances physical parameter anisotropy, which provides channels for carrier migration, while suppressing lattice scattering and non-radiative relaxation.These phosphors are further used for high-level anti-counterfeiting. This study firstly reveals that the large anisotropy of physical quantities induced by Cr3+ substitution for Ga3+ is responsible for the strong afterglow effect in Cr-activated Gabased materials.
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高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zi-Jin Wei,Chang Yin,Mengjie Sun,Kai Long,Zhouyu Zhang,Zichao Yan,Wei Wang,Zhi Yuan
Due to their unique afterglow ability, long-wavelength-light rechargeable persistent luminescence (PersL) nanoparticles (PLNPs) have been emerging as an important category of imaging probes. Among them, ZnGa2O4:0.6% Cr3+ (ZGC) PLNPs have gained widespread recognition due to the ease of synthesis and uniform morphology. Unfortunately, the limited absorption arising from the low molar extinction coefficient of Cr3+ results in relatively low afterglow intensity and rapid decay after long-wavelength LED light irradiation. Herein, we discovered a strategy that boosting dye-sensitization performance was able to effectively amplify the PersL signal under white LED light. Specifically, Dil served as a highly efficient sensitizer for Cr3+, promoting the absorption of the excitation light. By adjusting the Pr dopant concentrations, ZGCP0.5 PLNPs with optimal trap densities were obtained, which showed the highest PersL intensity and dye-sensitized performance. Strikingly, ZGCP0.5-Dil PLNPs exhibited a 24.3-fold enhancement in intensity and a 2-fold prolongation of decay time over bare ZGC PLNPs through the synergy effect of optimal electron traps and dye sensitization. Photostable ZGCP0.5-Dil PLNPs enabled imaging of the HepG2 tumor and effectively guided tumor surgical resection verified by the H&E staining analysis. This strategy could be a significant reference in other dye-sensitization PLNPs to enhance longer-wavelength rechargeable PersL.
研究领域:
材料科学
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生物医学工程
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光学成像
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产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
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2015
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IF 2.349
Chao Chen,Guizhi Li,Yanli Liu
Mass production of ZnGa 2 O 4 has been successfully achieved via a simple solid state reaction assisted by high-energy ball-milling of mixtures of ZnO and GaOOH powder at room temperature. The samples were characterized in detail to confirm the formation of ZnGa 2 O 4 . It could be concluded from the result of X-ray diffraction patterns that the crystal formation started after milling for 5 h, and it was completed after 7 h. The average diameter of the as-prepared ZnGa 2 O 4 is less than 100 nm. To demonstrate the potential applications, we have fabricated a gas sensor based on the as-synthesized ZnGa 2 O 4 and investigated it for liquid petroleum gas (LPG) and nitrogen dioxide gas (NO 2 ) detection at different working temperatures. ZnGa 2 O 4 sensors exhibited a gas response ( R a / R g = 7.9, R a : resistance in air, R g : resistance in gas) to 50 ppm of LPG at working temperature 340 °C, and a superior gas response ( Rg / Ra = 16.2) to 5 ppm of NO 2 at 240 °C. Preliminary functional tests indicated promising sensing responses and the possibility of discriminating between reducing and oxidizing species as a function of the working temperature.
研究领域:
材料科学
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气体传感技术
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纳米材料合成
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DOI
高影响因子
Journal of Materials Chemistry C
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2022
·Vol. 10
·期 15
·5829-5839
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IF 8.067
Cheng Zhou,Lu Peng,Zihui Kong,Meihan Wu,Maxim S. Molokeev,Zhi Zhou,Jing Wang,Mao Xia
Cationic substitution is a common material modification strategy. Generally, it follows the principles of radius matching, valency equilibrium and stoichiometric substitution. However, radius-mismatched, nonstoichiometric-ratio ion substitution can achieve unexpected experimental results. Such unexpected results are very important for expanding the research of materials, but the modification mechanism is still unclear. In this work, the optical performance of ZnGa2O4:0.02Cr3+ (ZGO:0.02Cr3+) is effectively regulated by chemical unit cosubstitution (Ge4+–Li+/Na+ for Ga3+–Zn2+) and excess cation substitution synergetic strategies, and the thermal stability is retained at 97.7% at room temperature and 150 °C. Ge4+–Li+ and Ge4+–Na+ replace the lattice position of Ga3+–Zn2+ to enhance the photoluminescence (PL) intensity and quantum efficiency (QE) of ZGO:0.02Cr3+. The optimal doping contents of Ge4+–Li+ and Ge4+–Na+ are all 0.3 mol (PL intensity is 130.3% and 153.4% and QE = 77.4% and 85.1%). With further addition of Li+ ions, the emission intensity and QE continued to increase to 176.4% and 83.8%, respectively. The synergistic effect of the mechanism on optical properties is explained via Rietveld refinement, optical band gap energy and thermoluminescence. Finally, LED devices were fabricated by using the ZGO:0.02Cr3+,0.03Ge4+,0.11Li+ phosphor to investigate the effect on plant growth. The growth period was reduced and the fruit quality was improved in dwarf potted tomato, which shows the application prospect in plant growth of the ZGO:0.02Cr3+ phosphor.
研究领域:
材料科学
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植物学
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光学工程
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2026
·
IF 4.6
Xiaomeng Wang,Jiaren Du,Ke Chen,Lejia Cao,Puxian Xiong,Bruno Viana,Hengwei Lin
Self-activated luminescent materials have attracted increasing attention due to their broad applicability across diverse technological fields. However, a comprehensive understanding of the generation, regulation, and coexistence of self-activated luminescent centers with dopant-related emission centers remains limited. Herein, a defect-related self-activated blue-emitting center (with peak position located in the 450–500 nm range) is induced within the conventional spinel gallate phosphor system via a microwave-assisted preparation process. Notably, the self-activated emission universally coexists with the characteristic transitions of different dopant ions (Eu3+/Mn2+/Cr3+), indicating excellent compatibility between self-activated luminescent centers and multiple dopant-related emission centers. Taking ZnGa2O4:Cr3+ as an example, the self-activated luminescence shows pronounced dependence on both irradiation time and temperature. Further investigations elucidate that the electron trapping and detrapping pathways are associated with the coexisting self-activated and dopant-related luminescent centers, highlighting the distinct electron dynamics arising from their coexistence. Moreover, benefiting from the different temperature responses, a dual-emission ratiometric thermometry platform with a wide operating temperature range from 143 to 573 K is constructed. This work emphasizes the unique electron dynamics of self-activated luminescent centers and demonstrates their broad compatibility with diverse dopant systems, providing insights into the design of multifunctional luminescent materials based on intrinsic defect states.
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DOI
PubMed
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 15
·2303018
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IF 8
Xueqing Liu,Lu Chen,Xiaowen Huo,Feng Liu,Chuan Liao,Liangliang Zhang,Jiahua Zhang,Shaoan Zhang,Yang Li,Xiao-jun Wang,Yichun Liu
The ZnGa 2 O 4 :Cr 3+ phosphor has emerged as a significant luminescent material due to its long-lasting afterglow and near-infrared emission, making it suitable for applications in bioimaging and night-vision detection. However, the limited availability of excitation light sources poses a challenge for charging the phosphor. In this study, the charging capabilities of ZnGa 2 O 4 :Cr 3+ using visible lasers and a white flashlight as excitation sources are explored. By absorbing two excitation photons, the high-lying delocalized state of Cr 3+ can be excited through a two-step process, resulting in the filling of persistent luminescence traps and producing a long-lasting emission peaking at 696 nm. The application of the white flashlight revealed a nonlinear excitation threshold for charging at 1.5 mW cm −2 . The findings also uncovered that the excitation mechanism involves excited-state absorption and energy-transfer upconversion. Moreover, taking advantage of the unique excitability of the near-infrared persistent phosphor, the potential for charging persistent luminescent probes in vivo using chicken breast tissue as a representative model is showcased. The present upconversion charging approach may offer promising possibilities and introduce a novel excitation technique for ZnGa 2 O 4 :Cr 3+ persistent phosphor.
研究领域:
材料科学
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光子学
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发光材料
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生物成像
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光学传感
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2016
·
IF 2.264
Jin Liu,Wei Lu,Hongzhang Wu,Lin Jin,Bin Hu,Lili Li,Zhenling Wang
Rice-like HT-ZnGa 2 O 4 were successfully synthesized by using commercially available Ga 2 O 3 as an in situ sacrificial templates. The composition, morphology and microstructure of rice-like HT-ZnGa 2 O 4 were characterized in detail. Rice-like HT-ZnGa 2 O 4 were found to be composed of hundreds of nanoparticles . The pH-dependent experiment results indicated that the dispersive rice-like HT-ZnGa 2 O 4 was obtained at pH 8.0. The photocatalytic degradation results showed that the rice-like HT-ZnGa 2 O 4 exhibited high photocatalytic activity and excellent stability for the photocatalytic removal of organic and inorganic pollutants in solution. Finally, the mechanism involved in the photocatalytic process have been investigated by theory and experiment analyses.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
RSC Advances
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2022
·Vol. 12
·期 54
·35064-35071
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IF 4.036
Ailijiang Tuerdi,Peng Yan,Fenggui He,Abdukader Abdukayum
The development of new photocatalysts with high photocatalytic efficiency and catalytic stability, and long persisting luminescence is critical for ensuring environmental protection and clean energy production. In this study, we develop a flower-like In2O3/ZnGa2O4:Cr heterojunction composite with enhanced ultraviolet (UV) photocatalytic activity using a facile two-step hydrothermal method. The spectral response range of the heterojunction composite is widened to the visible-light range owing to the presence of the ZnGa2O4:Cr persistent luminescence nanoparticles with sizes of less than 10 nm. The heterojunction composite is dispersed on the flower petals of In2O3. The In2O3/ZnGa2O4:Cr/1:1 composite exhibits photo-degradation performance for rhodamine B degradation that is superior to those of pure In2O3, ZnGa2O4:Cr, In2O3/ZnGa2O4:Cr/1:0.5 and In2O3/ZnGa2O4:Cr/1:2, achieving complete degradation after 80 min under UV light irradiation. Moreover, it exhibits long afterglow luminescence that lasts for more than 72 h. Thus, the In2O3/ZnGa2O4:Cr/1:1 composite shows great potential for use in round-the-clock photocatalytic applications.
研究领域:
材料科学
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环境科学
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光催化技术
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产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 45
·18987-18994
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IF 7.76
Huai-Xin Zhao,Cheng-Xiong Yang,Xiu-Ping Yan
Persistent luminescent nanoparticles (PLNPs) show great potential in realizing precision imaging due to the absence of in situ excitation and no background interference. However, the current PLNP-based tumour imaging is usually achieved by single targeting or passive targeting strategies, and thus it lacks high specificity and affinity for efficient persistent luminescence imaging in vivo. Herein we report the bioconjugation of multiple targeting ligands on the surface of PLNPs for dual-targeted bioimaging to improve the specificity and affinity of the PLNP nanoprobe for in vitro and in vivo bioimaging. The PLNPs were prepared by co-doping CrIII and BIII into ZnGa2O4via a hydrothermal–calcination method. While CrIII doped ZnGa2O4 PLNPs possess excellent near-infrared luminescence along with long afterglow and red light renewable near-infrared luminescence, doping of BIII into the PLNPs further improves the persistent luminescence. Conjugation of two targeting ligands, hyaluronic acid and folic acid, which have specificity toward the cluster determinant 44 receptor and folic acid receptor in tumour cells, respectively, provides synergistic targeting effects to enhance the specificity and affinity toward tumour cells. This work provides a dual-targeting strategy for fabricating PLNP-based nanoprobes to realize precision tumour-targeted bioimaging.
研究领域:
材料科学
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生物医学工程
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癌症研究
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）