ADVANCED MATERIALS
·
2025
·
IF 26.8
Na Lin,Li Xiao,Yishi Wu,Yi-Fan Wu,Zi-Xian Li,Tian-Yu Yan,Zhi-Wei Chen,Cheng-Yang Yue,Dongpeng Yan,Xiao-Wu Lei
Excitation- and temperature-dependent multicolor luminescent materials are valuable in advanced optoelectronic devices while they haven't been realized in 2D metal halides owing to the restrictions of Kasha's rule. Herein, we reported a novel 2D lead-free halide of (AMP) 2 Cu 2 Br 4 (AMP = N-aminomorpholine) through structural engineering, in which the [Cu 2 Br 4 ] 2− layer is composed of corner- and edge-shared [CuBr 4 ] tetrahedron. The non-centrosymmetric structure enables (AMP) 2 Cu 2 Br 4 to exhibit an impressive second-harmonic generation signal of ≈0.8 times that of KH 2 PO 4 (KDP). Remarkably, (AMP) 2 Cu 2 Br 4 possesses two independent self-trapped exciton-emitting states under different excitation energies, which display multicolor luminescence outputs from blue, white, to orange with near-unity photoluminescence quantum yields (PLQYs). Additionally, the luminescence can be regulated in a wide temperature range of 300–400 K due to reversible energy transfer between two emitting bands, acting as a luminescence ratio thermometer with a ultrahigh relative thermal sensitivity of 56.755% K −1 . High PLQY and large Stokes shift further endow (AMP) 2 Cu 2 Br 4 strong radioluminescence with an ultrahigh light yield of 92,400 photons·MeV −1 , low detection limit of 121 n Gy air ·s −1 and a short afterglow of 0.41 m s. The abundant photophysical properties highlight the multiple optoelectronic applications of 2D cuprous halide in white light-emitting, laser technology, flexible temperature sensors, and X-ray imaging.
研究领域:
材料科学
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光电子学
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凝聚态物理
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无机化学
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功能材料
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辐射探测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 29
·15791-15799
·
IF 6.895
Hao-Hua Deng,Qiong-Qiong Zhuang,Kai-Yuan Huang,Paramasivam Balasubramanian,Zhen Lin,Hua-Ping Peng,Xing-Hua Xia,Wei Chen
As a new emerging candidate for solid-state phosphors, copper nanoclusters (CuNCs) have gained tremendous interest in the field of white light-emitting devices (WLEDs). However, their further applications are impeded by the low photoluminescence quantum yield (PLQY) and poor emission color tunability of CuNCs. This work demonstrates the synthesis of cyan and orange emitting CuNCs, and their combination as color conversion phosphors in WLEDs. The cyan and orange emitting CuNCs were prepared employing 2-mercapto-1-methylimidazole (MMI) and N-acetyl-L-cysteine (NAC), respectively, as stabilizing-cum-reducing agents. The dispersions of MMI-CuNCs and NAC-CuNCs are weakly emissive. However, after processing into powders, they both possess ultrahigh PLQYs (45.2% for MMI-CuNCs, and 64.6% for NAC-CuNCs) owing to the effect of aggregation-induced emission (AIE). All-CuNC based WLEDs are then designed and developed using powdered MMI-CuNC and NAC-CuNC samples on commercially available 365 nm GaN LED chips. They display acceptable white light characteristics with a Commission Internationale de l'Eclairage coordinate value and color rendering index of (0.26, 0.30) and 83, respectively. We believe that these cost-effective and eco-friendly CuNCs with interesting AIE properties will vigorously promote the development of high-quality WLEDs for commercial applications.
研究领域:
材料科学
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光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Dunpu Zhang,Zhen Yue,Zhengyang Liu
Currently, FIR-based luminescent nanothermometry has aroused wide concern for its promising applications in fast-moving objects, harsh environments and microscopic temperature. Synchronously promoting the absolute and relative sensitivities of optical thermometers is one of the significant issues at present. In this work, a new nanothermometry strategy to possess both high absolute and relative sensitivities have been proposed by coupling of thermally-coupled-levels-based technique with non-thermally-coupled-levels method in the core-shell designed nanomaterials . Following this strategy, the core-shell-structured NaGdF 4 :Yb,Er@ NaYF 4 :Ce,Tb,Eu nanocrystals have been successfully prepared. Remarkably, the adverse cross-relaxation among different activators is extremely suppressed owing to the spatial separation of Er 3+ and Eu 3+ ,Tb 3+ activators, being conducive to the realization of both intense green upconverting emissions and yellow downshifting luminescence. Moreover, the temperature-sensitive dual-mode luminescent behaviors of core-shell nanomaterials are systematically studied to probe the possible application in FIR-related luminescent thermometry. Specially, the thermally-coupled-levels-based FIR of Er 3+ : 2 H 11/2 → 4 I 15/2 transition to Er 3+ : 4 S 3/2 → 4 I 15/2 one and non-thermally-coupled-levels-based FIR of Eu 3+ : 5 D 0 → 7 F 2 transition to Tb 3+ : 5 D 4 → 7 F 6 one are proved to be applicable as temperature probes, leading to the achievement of dual-mode temperature sensing. Using the pre-designed core@shell nanoarchitectures, the absolute sensitivity can reach up to 1.02% K −1 based on Eu 3+ ,Tb 3+ Stokes emissions and the relative sensitivity could reach as high as 1.12% K −1 based on Er 3+ anti-Stokes luminescence. We believe that this study provides a valid approach for developing high-performance optical nanothermometers.
研究领域:
材料科学
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光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 26
·期 3
·2472-2477
·
IF 3.3
Yingui Gao,Zhihuang Xu,Liwang Ye,Yuanjie Wang,Xinxin Zhuang
Lead-free metal halides are considered as alternatives to lead-based perovskites due to their low toxicity, rich structural diversity, and high luminescence properties. We report millimeter-sized single crystals of a new zero-dimensional (0D) copper(I)-based hybrid material, (AEP)2Cu2Br6·2Br·2H2O (AEP = C6H18N33+), which exhibits bright broadband green photoluminescence (PL) at 510 nm with a Stokes shift of 220 nm and a PL lifetime of 121.1 μs. Density functional theory (DFT) calculations and experimental studies reveal that the green light can be attributed to self-trapping exciton (STE) emission. It is worth mentioning that this crystal has a high photoluminescence quantum yield (PLQY) of 90.5%, which is higher than most copper halides.
研究领域:
材料科学
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光电学
·
光子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yiping Wu,Meng Wu,Shiwei Yang,Cong He,Chunwen Ye,Yanjie Zhang
Herein, a series of Mn-activated ZnGa2O4 (ZGO) phosphors have been developed for multifunctional applications. The characteristic green and red emission at 503 and 668 nm of Mn-activated ZGO phosphors can be observed under excitation of 247 and 375 nm, respectively, attributed to the partial oxidation of Mn2+ ions resulting in the coexistence of Mn2+ and Mn4+ ions in the host lattice. The valence modulation of Mn content not only realizes the adjustment of red and green luminescence intensity but also achieves the management of persistent luminescence time and thermo-luminescence time. Further, the codoping of Mg2+ could transform the position occupancy preference of Mn and effectively facilitate the conversion of Mn2+ to Mn4+, leading to the regulation of the valence state of manganese ions. Surprisingly, the existence of Mg2+ ions broadens the emission band of Mn4+ and enhances the photoluminescence intensity to 3.8 times, which can be ascribed to the weakened crystal field leading to the downward shift of the 4T2 energy level and the increase of Mn4+ concentration. For this valence modulation behavior, two different hypotheses about the occupancy of Mg2+ have been proposed to explain the corresponding phenomenon. Finally, the potential applications of the synthesized phosphors have been explored in advanced anticounterfeiting strategies, information storage, and plant lighting field.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Hongshi Zhang,Jiyou Zhong,Fu Du,Lei Chen,Xiaoli Zhang,Zhongfei Mu,Weiren Zhao
Broad-band near-infrared (NIR) phosphors are essential to assembling portable NIR light sources for applications in spectroscopy technology. However, developing inexpensive, efficient, and thermally stable broad-band NIR phosphors remains a significant challenge. In this work, a phosphate, KAlP2O7, with a wide band gap and suitable electronic environment for Cr3+ equivalent substitution was selected as the host material. The synthesized KAlP2O7:Cr3+ material exhibits a broad-band emission covering 650–1100 nm with a peak centered at 790 nm and a full width at half-maximum (fwhm) of 120 nm under 450 nm excitation. The internal quantum efficiency (IQE) was determined to be 78.9%, and the emission intensity at 423 K still maintains 77% of that at room temperature, implying the high efficiency and excellent thermal stability of this material. Finally, a NIR phosphor-converted light-emitting diode (pc-LED) device was fabricated by using the as-prepared material combined with a 450 nm blue LED chip, which presents a high NIR output power of 32.1 mW and excellent photoelectric conversion efficiency of 11.4% under a drive current of 100 mA. Thus, this work not only provides an inexpensive broad-band NIR material with high performance for applications in NIR pc-LEDs but also highlights some strategies to explore this class of materials.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 22
·7623
·
IF 4.6
Yangbo Wang,Yingdong Han,Runfa Liu,Cunping Duan,Huaiyong Li
Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb3+/Eu3+-doped CaZrO3in detail. The intrinsic purple-blue luminescence from host CaZrO3and the introduced green/red luminescence from guest dopants Tb3+/Eu3+were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb3+/Eu3+-doped CaZrO3. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption.Keywords:luminescence;lanthanide;multicolor emission;luminescence regulation;information encryption
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 22
·7666-7673
·
IF 7.367
Xin Su,Xiaoqian Sun,Suli Wu,Shufen Zhang
Photonic crystals (PCs) have long been considered effective for tuning upconversion luminescence due to their photonic band gap (PBG) and the redistribution of density of optical states (DOS). Although the emission intensity can be changed obviously by the PC effect, rarely an obvious lifetime change consistent with theory is observed due to the low refractive index of PS or SiO2 spheres in the commonly used PCs. Herein, CdS/NaYF4:Yb3+,Er3+ composite PCs with a high refractive index contrast are fabricated in one step with upconversion nanoparticles filled inside CdS PCs. When the upconversion emission peak lies at the edge of the PBGs of the composite PCs, a dramatic decrease in lifetime by 28% and 41% is observed for the green and red emissions, respectively. At the same time, obvious emission intensity enhancements are also observed. In contrast, PS PCs with a low refractive index contrast show a slight effect on the lifetime of upconversion luminescence with their emission peak at the edge of the PBGs. Our results agree well with theory and prove that a sufficiently large refractive index contrast is necessary for PCs to dramatically tune the luminescence lifetime and intensity simultaneously.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Xiaohui Lai,Zhiyong Fang,Jian Zhang,Bo Wang,Wenfeng Zhu,Rui Zhang
A novel BaLu 2 Al 2 Ga 2 SiO 12 :Ce 3+ persistent phosphor was designed and synthesized through hetero-valence substituting Ba 2+ -Si 4+ ion pair for Lu 3+ -Al 3+ one in the Lu 3 Al 3 Ga 2 O 12 . XRD and Rietveld refinement results confirm the garnet typed crystal structure. SEM information shows that the constituent elements are uniformly distributed on the irregular particles. Under 360 or 430 nm excitation, the samples exhibit broad emission bands peaking at 510 nm. The luminescence intensity reaches to the maximum at 6 mol% Ce 3+ doping content, and an internal quantum efficiency of 51.2% is achieved. The concentration quenching between Ce 3+ ions is mainly originated from exchange interaction. Moreover, the phosphors exhibit bright cyan afterglow for minutes after removing the blue-light excitation source. The persistent luminescence decay process is studied by thermoluminescence spectra. The persistent luminescence mechanism and optical information writing and reading process are also discussed to explore the application in optical information storage.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2014
·
IF 2.367
Jiansheng Huo,Jiadan Zhu,Shunhua Wu,Haijie Zhang,Qianming Wang
Red emissive phosphors of YTa 1− x Nb x O 4 :Eu 3+ ( x =0–1) have been successfully synthesized by a molten salt method. Powder characteristics were studied by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. The effects of Nb concentration ( x ), flux nature and firing temperature on photoluminescence behavior of YTa 1− x Nb x O 4 :Eu 3+ were extensively investigated. The results showed that the photoluminescence spectra of the samples exhibited strong red emissions (615 nm) upon the ultraviolet excitation and the emission intensities strongly dependent on the host-lattice composition and particle morphology .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Sihan Yang,Xuyan Xue,Feng Jiang,Liang Dong,Qi Zhu,Xuejiao Wang,Ji-Guang Li
The emission wavelength of current near-infrared phosphors activated by Cr 3+ is generally smaller than 900 nm in near-infrared (NIR) I region, and it is extremely challenging and is of great practical significance to realize emission towards NIR-II region. In this study, a novel Cr 3+ excited KSrScSi 2 O 7 silicate broad-band phosphor was prepared using the traditional solid-state method. Cr 3+ resides in a weak crystal field in the KSrScSi 2 O 7 lattice and exhibits broad-band near-infrared emission at 984 nm, longer than those of most Cr 3+ activated phosphors, under 493 nm blue light excitation. This is due to the strong charge polarization caused by the unique local coordination environment of the silicate matrix, which leads to a reduction in the crystal field splitting energy of the [ScO 6 ] octahedron where Cr 3+ is located and the downward shift of the 4 T 2 energy level. The optimal doping concentration of Cr 3+ is found to be 2 mol%, and the quenching mechanism is dipole-dipole interaction. Compared to the phosphors with similar emission wavelengths ( λ em > 900 nm), KSrScSi 2 O 7 :Cr 3+ demonstrates outstanding advantages in various aspects of luminescent performance. The fabricated phosphor-converted light-emitting diode (pc-LED) is shown to have the potential for night vision and non-invasive imaging. Novel application of KSrScSi 2 O 7 : x Cr 3+ as stable green ceramic pigments is also explored. The KSrScSi 2 O 7 : x Cr 3+ powders show a bright yellowish green appearance, and the KSrScSi 2 O 7 :0.02Cr 3+ typical composition has chromaticity values of L* = 82.73, a* = –8.53, b* = 7.97. Remarkably, the glazing samples using KSrScSi 2 O 7 : x Cr 3+ as pigments well retain the bright color after 1200 °C sintering in different atmospheres. Therefore, multi-functional applications of KSrScSi 2 O 7 : x Cr 3+ for near-infrared spectroscopy and as ceramic pigments are achieved in this work.
研究领域:
材料科学
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光学
·
陶瓷科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Xiaoqing Sun,Jing Lei,Yan Jin,Baoxin Li
Most of the known chemiluminescence (CL) systems are flash-type, whereas a CL system with long-lasting and strong emission is very favorable for accurate CL quantitative analysis and imaging assays. In this work, we found that the oxidized g-C3N4 (g-CNOX) could trigger luminol-H2O2 to produce a long-lasting and intense CL emission. The CL emission lasted for over 10 min and could be observed by the naked eye in a dark room. By means of a CL spectrum, X-ray photoelectron spectra, and electron spin resonance spectra, the possible mechanism of this CL reaction was proposed. This strong and long-duration CL emission was attributed to the high catalytic activity of g-CNOX nanosheets and continuous generation of reactive oxygen species from H2O2 on g-CNOX surface. Taking full advantage of the long-lasting CL property of this system, we proposed one “non-in-situ mixing” mode of CL measurement. Compared with the traditional “in-situ mixing” CL measurement mode, this measurement mode was convenient to operate and had good reproducibility. This work not only provides a long-lasting CL reaction but also deepens the understanding of the structure and properties of g-C3N4 material.
研究领域:
化学
·
材料科学
✓ 已验证
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）