CRYSTAL RESEARCH AND TECHNOLOGY
·
2022
·Vol. 57
·期 4
·2100162
·
IF 1.599
Yanli Ding,Zhaohan Li
The low luminous efficiency of upconversion materials limits their practical applications in various fields. The present study focuses on the efficient upconversion enhancement of β-NaYF 4 :Yb,Er induced by Bi 3+ doping. The XRD and SEM results show that introducing Bi 3+ into the matrix lattice changes the microstructure and particle size of the crystal. The photoluminescence spectra show that at 6% Bi 3+ doping, the red and green emission intensities are enhanced by 12 and 8 times, respectively. The reason could be the lattice distortion caused by Bi 3+ doping, breaking the partial forbidden transition of rare-earth ions. The fluorescence lifetime measurement reveals that the Bi 3+ doping changes the environment around erbium ions, affecting the energy level lifetime of erbium ions, explaining the luminescence dynamics law. The present study provides a facile route to achieve nano/microstructures with intense upconversion luminescence with potential applications in optoelectronic devices.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 31
·15192-15199
·
IF 3.925
Zhihui Rao,Zhilin Li,Xiujian Zhao,Xiao Gong
Cs2AgInCl6 lead-free double perovskites are environmentally benign with easily modulated fluorescence. However, their wide band gap (∼3.3 eV) and forbidden optical transitions limit their visible application. Herein, we prepared Cs2AgInCl6 microcrystals (MCs) and corresponding doped samples (bismuth: Bi3+, samarium: Sm3+, and Bi3+–Sm3+) to achieve such a functionality by a precipitation method at low temperature (80 °C). Bi3+-doped Cs2AgInCl6 MCs introduce 1S0 to 1P1 absorption with a fluorescence enhancement at lower excitation energy (370 nm). Although the f–f transition of Sm3+ is parity forbidden, Bi3+–Sm3+ co-doped Cs2AgInCl6 MCs show a combination of luminescence in the visible range with two sharp additional spectral features at 567 and 600 nm, which are attributed to the 4G5/2 → 6H5/2 (∼567 nm) and 4G5/2 → 6H7/2 (∼600 nm) transitions of Sm3+ ions. We proposed a mechanism in which Cs2AgInCl6:Bi–Sm MCs achieve mutual enhancement of fluorescence through recombination of self-trapped excitons and energy-transfer transitions. Moreover, thermogravimetric (TG) analysis indicated that the materials have remarkable thermal stability. Afterwards, light-emitting diodes (LEDs) with bright yellow light were fabricated by combining Cs2AgInCl6:Bi–Sm MCs with a 365 nm chip, and the corresponding color coordinate is about (0.535, 0.440) with a 2000 K correlated color temperature (CCT).
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 48
·2412099
·
IF 27.4
Hongzhi Zhang,Hong Li,Junpeng Li,Conglin Liu,Hongming Jiang,Yuxin Liu,Rui Wang,Jiyang Xie,Wanbiao Hu,Jing Zhu
Achieving single-phase full-spectrum white light (SFWL) phosphors is a central goal in the optical field because they simplify white-LEDs assembly and avoid long-term color instability. Despite many approaches are developed, current SFWL phosphors still suffer from chromaticity drift due to inconsistent thermal quenching of multiple emitting centers. Herein, an absolutely structural disorder strategy is established to develop a single-emitting center-based SFWL phosphor. Precisely controlling the flux added induces a structural translation from the absolutely ordered Y 0.75 Ta 0.25 O 1.75 :Bi 3+ to the absolutely disordered Y 0.785 Ta 0.215 O 1.715 :Bi 3+ , as directly identified by STEM-HAADF analyses. Structural disorder enables Y 0.785 Ta 0.215 O 1.715 :Bi 3+ to produce SFWL with the FWHM of 6194 cm −1 (175 nm) by employing a single activator site, a 1352 cm −1 increase compared to the cyan-emitting Y 0.75 Ta 0.25 O 1.75 :Bi 3+ despite Bi 3+ occupies two lattice positions. This single-emitting center-based SFWL, coupled with minimal thermal expansion of the unit cell and inapparent spectral overlap of excitation and emission bands, ensure zero-chromaticity shift with elevated temperature. A prototype white-LEDs using Y 0.785 Ta 0.215 O 1.715 :Bi 3+ as a single luminescent layer generates warm white light without perceptible CIE coordinates shift under various currents or after extremely long-term continuous operation. This work highlights the potential of structural disorder in designing SFWL phosphors with exceptional color stability.
研究领域:
光学材料
·
发光学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Yun-Ling Yang,Ting Li,Fan Guo,Jia-Yong Yuan,Chong-Hao Zhang,Yu Zhou,Qian-Li Li,Dong-Yun Wan,Jing-Tai Zhao,Zhi-Jun Zhang
Mechanoluminescence materials that emit light under mechanical stimulation have attracted widespread attention in sensing, anticounterfeiting, and imaging applications. In this study, a series of Sr1–xBixZnSO (0.001 ≤ x ≤ 0.1) samples was synthesized by the method of high temperature solid-state reaction. It is worth noting that the distortion degree of the SrO3S3 octahedron was increased with increasing Bi3+ concentration, and the color manipulated Sr1–xBixZnSO which can emit different photoluminescence (blue to dark blue and finally red) and mechanoluminescence (orange to red) colors is obtained. Moreover, the deep traps can stably store and provide electronic supplements in shallow traps released under mechanical stimulation. Therefore, devices made of SrZnSO:Bi3+ phosphor and polydimethylsiloxane (PDMS) can be used as thermo-mechano-opto three-mode anticounterfeiting. The ML intensity is linear to the external load and can be utilized for stress sensing or imaging.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 5
·2607-2618
·
IF 2.779
Gao Zhihua,Fu Fengyan,Niu Lili,Jin M.
In the recent years, luminescent phosphor materials have contributed much to reduce the serious environmental problems such as environmental pollution, greenhouse effect, and energy crisis, but most of them commercially used for fabricating white LEDs are rare earth (RE) ions doped materials. Here, the non-RE Bi 3+ -doped Ba 2 (Y,Sc)NbO 6 solid solution nanocrystals are prepared using a high temperature solid state route followed by a ball milling and griddle selection. Our experiments show that when the Y 3+ ions are replaced by the Sc 3+ ions, the obtained solid solution nanocrystals show a shift of X-ray reflection positions to higher angle, and the emission peaks from blue to blue-green. At the same time, a 1.35 time of PL intensity enhancement under 365 nm excitation is achieved in the Ba 2 (Y 0.58 ,Sc 0.4 )NbO 6 :0.02Bi sample when compared to the Ba 2 Y 0.98 NbO 6 :0.02Bi sample. In addition, this optimal sample shows the quantum efficiency of 76% and good thermal stability with T 50% value of 205 °C. By depositing the Ba 2 (Y 0.58 ,Sc 0.4 )NbO 6 :0.02Bi and commercial red Sr 2 Si 5 N 8 :Eu 2+ phosphors on a 365 nm UV LED chip at a driving current of 30 mA, a white LED device, with a CIE coordinates at (0.364, 0.379), a high color rendering index of 76.8 and luminous efficiency of 67 lm, and a low color temperature of 3469 K, is achieved.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yiping Wu,Meng Wu,Jingjie Yu,Yuru Wang,Jinlong Wang,Yingwei Xu,Yanjie Zhang
Optical information encryption based on luminescence materials have received much attention recently. However, the single luminescence mode of the luminescence materials greatly limits its anti-counterfeiting application with high safety level. Here, a series of luminescence materials of Tb 3+ and Bi 3+ co-doped ZnGa 2 O 4 phosphors with great correspondence in photoluminescence (PL), persistent luminescence (PersL), and thermoluminescence (TL) modes was synthesized by the conventional solid-phase method for the application in multi-modal anti-counterfeiting fields. Under the excitation of 254 nm, ZnGa 1.99 O 4 :0.01 Tb 3+ , yBi 3+ (y = 0.001,0.002) sample exhibited a broad blue emission band (the transition from [GaO 6 ]) at 440 nm and the characteristic emission peaks of Tb 3+ at 495 nm, 550 nm, 591 nm and 625 nm, corresponding to the transitions of 5 D 4 - 7 F n (n = 6, 5, 4, 3), respectively. Interestingly, the co-doping of Bi 3+ ions improve the crystallinity and particle size of the phosphor, subsequently enhanced the PL intensity of Tb 3+ to 6 times that of Tb 3+ singly doped ZnGa 2 O 4 phosphor. Further, the flexible films with multi-modal luminescence properties have been fabricated through the unique TL and PersL characteristics of ZnGa 2 O 4 : Tb 3+ , Bi 3+ phosphors, including “Optical information storage film”, “snowflake and characters” and “QR code”. Moreover, a set of optical information encryption is obtained by combining ZnGa 2 O 4 :Tb 3+ , Bi 3+ phosphor and red emitting phosphor. The results indicate that ZnGa 2 O 4 :Tb 3+ , Bi 3+ phosphor with multi-modal stimulus response can be expected to be potentially used in the applications of optical information storage and anti-counterfeiting fields.
研究领域:
材料科学
·
光学工程
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2023
·
IF 8.6
Shuai Wei,Zeyu Lyu,Zheng Lu,Pengcheng Luo,Luhui Zhou,Dashuai Sun,Taixing Tan,Sida Shen,Hongpeng You
Trap engineering is widely applied to contend with thermal quenching of phosphors. However, the incidental detriment of the luminescent efficiency has long been neglected. Herein, we propose a paradigm for achieving a high-performing Bi3+-doped phosphor with moderate trap engineering. Through introducing appropriate traps in a neutral atmosphere and proper doping concentration, we have successfully created a novel Ba2GdAlO5:Bi3+ yellow phosphor that exhibits exceptional thermal stability (104.1%@423 K) and a high internal quantum yield (82.78%), which is the top performance among Bi3+-doped phosphors. The oxygen vacancy and Bi2+ were identified as the responsible traps through X-ray photoelectron spectroscopy, while their depth was measured to be 0.9 eV by using thermoluminescence. Notably, the phosphor exhibited photochromism upon near-ultraviolet (n-UV) excitation and could be bleached through heat treatment. These observations highlight its potential for various applications. Finally, two white lighting devices with a color rendering index exceeding 90 were prepared with n-UV LED chips by applying Ba2GdAlO5:Bi3+ as one of the phosphors. This study not only provides a high-performance Bi3+-doped phosphor suitable for high-quality white LED (WLED) lighting but also proposes a methodology for designing phosphors with high efficiency and thermal stability..
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Bin Li,Chong Yang,Rongbo Ma,Bin Cao,Chaoyong Deng,Weichao Huang
Bi 3+ -doping luminescent materials have recently evoked considerable interest in versatile applications. In this work, we have developed a series of Bi 3+ -activated CaSrMSbO 6 (M = La, Gd, Y) phosphors with double perovskite structures, exhibiting blue emission from 350 nm to 500 nm. The emission spectral position and intensity of Bi 3+ ions can be tuned by changing excitation wavelength and doping concentrations. The relationship between the local crystal field environment and the luminescence properties is comprehensively analyzed. Importantly, optical temperature properties of CaSrLaSbO 6 : Bi 3+ were investigated and were found to reach a maximum relative sensitivity of 4.57 % K −1 at 298 K. Furthermore, the anti-counterfeiting ink was prepared using CaSrLaSbO 6 : Bi 3+ phosphors, and it showed tunable emission under different light stimulation. These results indicate that CaSrLaSbO 6 : Bi 3+ phosphors have application potential in optical temperature sensing and anti-counterfeiting.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Peipei Dang,Qianqian Zhang,Dongjie Liu,Guogang Li,Hongzhou Lian,Mengmeng Shang,Jun Lin
The equivalent or hetero-valent substitution strategy is an efficient method for stimulating photoluminescence tuning or optimizing the photoluminescence performances of phosphor materials. A new K 2 NiF 4 -type layered perovskite SrLaZnO 3.5 :Bi 3+ phosphor with broad-band yellow emission (558 nm) is first explored. Based on an efficient hetero-valent substitution strategy, a series of Sr 1- x La 1+ x ZnO 3.5+ x /2 :Bi 3+ (0 ≤ x ≤ 0.4) solid solution phases are successfully constructed. The different Bi 3+ local environments at two crystallographic sites and vacancy oxygen make the various distributions of emission and excitation spectra. Consecutive emission tuning from yellow (558 nm) to orange (585 nm), and improvement of emission intensity and internal quantum efficiency (IQE = 45%-64%) are achieved through La 3+ hetero-valent substitution for Sr 2+ in Sr 1- x La 1+ x ZnO 3.5+ x /2 :Bi 3+ (0 ≤ x ≤ 0.4). The structural stability and Bi 3+ occupation distribution in solid solution have been revealed by structural elaboration and crystal field regulation. Based on the both hetero-valent substitution and site-selective excitation strategies, a novel orange-red luminescence can be observed peaking at ~609 nm under near-ultraviolet light (~390 nm) excitation without visible absorption. The fabricated full-spectrum phosphor-converted white light-emitting diodes (pc-WLEDs) show outstanding warm white light, and a high color rendering index (Ra = 97.1, R9 = 98) is achieved, implying that the as-prepared Sr 1- x La 1+ x ZnO 3.5+ x /2 :Bi 3+ (0 ≤ x ≤ 0.4) phosphors can used as yellow/orange-red components in pc-WLED lighting. These results indicate that hetero-valent substitution can predict and control site preference of luminescent centers, providing a new way for optimizing phosphor materials for solid-state lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yan Yang,Huaiwu Zhang,Jie Li,Yiheng Rao,Gang Wang,Gongwen Gan
Miniaturization, high frequency capability, low loss, and matching impedance play critical roles in new generation antennas. Although ferrite ceramics show a great potential as antenna substrate materials, some challenges still remain associated with their application to high performance antennas. In this work, we synthesized Bi 3+ -substituted NiCuZn ferrite to adjust the microstructure, magnetic, and dielectric properties at low sintering temperatures . It is shown that Bi 3+ substitution not only enhances grain growth and compactness of NiCuZn ferrite at low sintering temperatures, but also effectively tailors the permeability, permittivity, and loss factor. In particular, NiCuZn ferrite doped with 0.025 wt%, of Bi 2 O 3 possesses excellent performance with high permeability (~29.1), high n factor (~22.76), appropriate matching impedance (Z factor = 1.28), and low loss tangents (tanδ μ = 0.00853, tanδ ε = 1.22683 × 10 -4 ). In addition, the dielectric loss is significantly reduced and becomes as low as magnetic loss at high frequencies; the typical tanδ ε reduces to 1.94 × 10 -6 , and tanδ ε / ε ´ is greatly decreases to 0.137 × 10 -6 at 50 MHz. Thus, Bi 3+ -adjusted NiCuZn ferrites open up new opportunities for applications in high-frequency LTCC antennas.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 42
·15413-15421
·
IF 4.39
Jingwei Liu,Yanjie Liang,Shao Yan,Dongxun Chen,Shihai Miao,Weili Wang
Luminescent materials that emit in the narrowband ultraviolet-B (NB-UVB; 310–313 nm) spectral region have attracted considerable attention due to their unique spectral features, which endow them with great potential applications in the fields of photochemistry and photomedicine. However, NB-UVB persistent luminescent materials are relatively lacking, especially materials that are excitable by natural sunlight. Here we report the NB-UVB persistent luminescence of Gd3+ in (Y,Gd)3Ga5O12:Bi3+ garnets by making use of the persistent energy transfer from Bi3+ to Gd3+. The optimal Bi3+ and Gd3+ concentrations for the maximum energy transfer efficiency are determined and persistent NB-UVB light emission with a peak wavelength at 313 nm and an afterglow time of more than 24 h is successfully achieved in the (Y,Gd)3Ga5O12:Bi3+ phosphor. More importantly, the as-synthesized NB-UVB persistent phosphors are also excitable by the widely available natural sunlight and exhibit exceptional NB-UVB persistent luminescence performance. Benefitting from the visible-blind emission feature, interference-free capability from indoor ambient light and self-sustained optical characteristic, the developed sunlight-excitable NB-UVB persistent phosphors here not only hold great promise for covert optical tagging applications, but also open new opportunities for optical data storage in a bright indoor environment.
研究领域:
材料科学
·
光物理学
·
生物医学工程
·
光学成像
·
药物递送系统
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 15
·5615-5622
·
IF 5.7
Qianrong Jin,Jinrong Shi,Jianwei Jin,Wenli Xu,Suqin Chen,Yuexiao Pan
Efficient and versatile materials that are both non-toxic and environmentally sustainable have become paramount in our pursuit of greener and more durable illumination solutions. In this study, we investigated the optical properties of rare-earth-based all-inorganic perovskite (AIP) crystal Cs2NaGdCl6 (CNGC) with various substitutions to explore its potential applications in lighting devices. The primitive crystal CNGC exhibits intrinsic blue emission due to its self-trapped excitons (STEs) but singly-doping with Bi3+ ions results in weak blue emission, indicating quenching of the STE emission. Alloying by introducing Ag+ ions into the CNGC:Bi3+ lattice, replacing the Na+ ions, caused the disruption of the crystal field symmetry, which lifts the parity-forbidden selection rule and allows for s–p transitions of the Bi3+ ions. Thus, the co-doping with Ag+ ions in addition to Bi3+ leads to intense broad-band warm white emission covering a wide spectral range of 470–800 nm, with a correlated color temperature (CCT) of 4512 K and a color rendering index (CRI) of 79. The findings from this study provide valuable insights for the development of efficient and high-quality lighting devices using a simple technique.
研究领域:
材料科学
·
光学
✓ 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）