OPTICS AND LASER TECHNOLOGY
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2020
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IF 3.233
Xiaoyong Huang,Shaoying Wang,Balaji Devakumar
Red-emitting phosphors are highly demanded as color converters for both white light-emitting diodes (LEDs) and plant growth LEDs. Herein, we reported on the discovery of novel Mn 4+ ions doped Ca 2 YTaO 6 double-perovskite red-emitting phosphors. These samples were successfully prepared via the high-temperature solid-state reaction method, and their phase purity was confirmed by powder X-ray diffraction (XRD) patterns. XRD Rietveld refinement results revealed that the title compound crystallized in monoclinic space group P 2 1 / n with lattice parameters of a = 5.59630(8) Å, b = 5.82308(8) Å, c = 8.07158(12) Å, α = γ = 90 ° , β = 89.9768(23)°, and V = 263.034(4) Å 3 . The Ca 2 YTaO 6 structure consisted of abundant [TaO 6 ] octahedrons, providing appropriate sites for Mn 4+ incorporation. As obtained by photoluminescence measurements, the Ca 2 YTaO 6 :Mn 4+ phosphors showed a broadband excitation spectrum in the 250–600 nm wavelength range with two peaks around 350 and 514 nm. Under the 350 nm excitation, they exhibited narrowband deep-red emissions in the 630–750 nm wavelength range peaking at 680 nm with full-width at half maximum (FWHM) of 36 nm, corresponding to the spin-forbidden 2 E g → 4 A 2g transition of Mn 4+ ions. The investigation of the doping concentration-dependent optical properties of Ca 2 YTaO 6 :Mn 4+ phosphors indicated the critical quenching concentration equal to 0.2 mol%. The dipole-dipole interaction between Mn 4+ activators was the major mechanism leading to the concentration quenching effect. The fluorescence decay lifetimes of Ca 2 YTaO 6 :Mn 4+ phosphors decreased from 0.34 to 0.201 ms with increasing Mn 4+ doping concentrations. The CIE chromaticity coordinates of these phosphors were calculated based on the emission spectra, and the color purity reached up to 98.3%. Besides, the internal quantum efficiency of the optimal Ca 2 YTaO 6 :0.2%Mn 4+ sample was measured to be 21%.
研究领域:
材料科学
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光学材料
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固态化学
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光子学
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发光二极管（LED）
✓ 已验证
DOI
高影响因子
ACS Applied Optical Materials
·
2023
·
IF 0
Zhennan Wang,Yi Wei,Zhiliang Ren,Wei Wang,Dong Tu,Guogang Li
Near-infrared (NIR) light serves a key role in many potential applications such as food analysis, biomedical devices, night vision, and so on. As an important component of NIR phosphor-converted light-emitting diodes (pc-LEDs), the adjustment of emission peak position and spectral width of Cr3+-doped phosphors is still considered to be a crucial challenge. Herein, the two emissions at 740 nm from [Cr1O6] and 830 nm from [Cr2O4] were realized to broaden the emission band in the Al2.26Ge0.74O4.87:Cr3+ (AGO:Cr3+) phosphor. Moreover, with increasing Cr3+-doped concentration, the crystal field strength decreases and energy transfer from [Cr1O6] to [Cr2O4] is enhanced. The emission peak originating from [Cr2O4] gradually becomes dominant, resulting in a spectral red shift and broadening. The optimized AGO:0.7% Cr3+ phosphor shows remarkable thermal stability, of which the integrated intensity at 373 K keeps 86% of the initial intensity at 298 K. Under 405 nm excitation, the internal quantum efficiency could reach 70% and the external quantum efficiency was measured to be 23%. The application of night vision can be implemented based on the AGO:Cr3+-fabricated NIR pc-LED. This work achieves simultaneous modulation of luminescence color and spectral width by controlling the Cr3+-doped concentration, which provides a feasible strategy for NIR emission adjustment.
研究领域:
材料科学
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光学材料
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固态照明
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光子学
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发光
✓ 已验证
DOI
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Liping Song,Sisi Liang,Wendong Nie,Xianguo He,Jie Hu,Fulin Lin,Haomiao Zhu
Recent decades have witnessed a major development in broadband near-infrared (NIR)-emitting phosphors because of their potential applications in real-time nondestructive examination. These applications require the emission spectra of phosphors to be as broad as possible for efficient performance. Therefore, a blue-light excited LiInF4: Cr3+ phosphor with a NIR emission covering 700–1400 nm is successfully synthesized. Under 470 nm excitation, it shows broadband emission peaked at 980 nm with the full-width at half maximum of 210 nm. The structure and crystal field environment are investigated in detail, and the LiInF4: Cr3+ possesses a weak crystal field strength and strong electron–phonon coupling. An efficient NIR phosphor-converted light-emitting diode (pc-LED) is fabricated by the prepared LiInF4: Cr3+ phosphor and commercial blue diode chip, generating a NIR radiant flux of 5.54 mW at 150 mA drive current. Finally, the NIR pc-LED is successfully applied to identify the blood vessel distribution of the hand. This work suggests the potential of LiInF4: Cr3+ phosphor in applications.
研究领域:
材料科学
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光学材料
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固态照明
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光子学
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生物医学成像
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2019
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IF 10.159
Wei Wang,Mengxuan Tao,Yixin Liu,Yi Wei,Gongcheng Xing,Peipei Dang,Jun Lin,Guogang Li
Controlling the site selection of activators via chemical substitution to optimize and design luminescence materials is an essential part of rare-earth-activated phosphors. Herein, we report the UCr4C4-type CsKNa2–yLiy(Li3SiO4)4:Eu2+ and CsKNa2(Li3Si1–zGezO4)4:Eu2+ phosphors, in which there are three crystallographic sites (Cs, K, and Na), and the site engineering for Eu2+ activators is utilized to tune the luminescence properties. First, Li+ ions are introduced to control the migration of Eu2+ ions from K sites to Na sites, realizing the spectral tuning from cyan narrow band [λem = 485 nm, full width at half-maximum (fwhm) = 27 nm] to green narrow band (λem = 526 nm, fwhm = 58 nm). Moreover, the variation of local lattice caused by Li+ ions improves the internal quantum yields from 39 to 82% as well as reduces the thermal quenching (90% @ 150 °C of integrated intensity at 20 °C). Second, the Ge4+ ions are introduced to control the shrinkage of the Na polyhedron for Eu2+ doping, leading to disappearance of the shoulder band in the green region. Simultaneously, the spectral blue shift should be ascribed to a synergistic effect of the reduction of crystal field splitting and Stokes shift. Thus, the blue-emitting CsKNa2(Li3GeO4)4:Eu2+ phosphor is obtained, which has only one symmetric blue emission at 458 nm with fwhm = 26 nm. By employing a 370 nm UV chip, the as-fabricated white light-emitting diodes using CsKNaLi(Li3SiO4)4:Eu2+ phosphor presents a superior luminous efficacy of 94.16 lm W–1, a corresponding color temperature of 5045 K, and a high color rendering index (95.8), demonstrating that the site engineering strategy based on the manipulation of chemical composition and crystal structure could be applied to tune spectral distribution and develop novel potential phosphors for practical optical application.
研究领域:
材料科学
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光学材料
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固态化学
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发光材料
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光子学
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无机化学
✓ 已验证
DOI
高影响因子
ACS Omega
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2018
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IF 0
Jia Du,Yiming Lu,Jian Zhang,Jinxin Wang,Yanfang Wang,Mao Li,Qidai Chen
Tuning optical limiting was achieved based on the nanostructural and synergistic effects of heterosized gold nanoparticles and fullerene on electrochemical assembly. In particular, with thicknesses of 200, 1, and 10 nm, heterosized AuNP multilayers with periodical pairs of layers present a superior threshold of 0.59 J cm–2 to monosized AuNP films with the values of 0.89–2.55 J cm–2, which was further significantly enhanced by the introduction of C70 with a significant threshold drop from 0.43 to 0.13 J cm–2, indicating that the reverse saturable absorption of C70 had a key contribution compared to the free carrier absorption of AuNPs. This paper not only demonstrates that the hybrid engineering of heterosized AuNPs into an identical film is an effective way to enhance the optical limiting but also indicates that the reverse saturable absorption of C70 is superior to free carrier absorption of AuNPs in optical limiting in AuNPs and C70 hybrid films.
研究领域:
纳米材料
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光子学
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光学材料
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纳米光子学
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电化学
✓ 已验证
DOI
ACS Applied Materials & Interfaces
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2023
·
IF 9.5
Jiawei Zhu,Lisu Yu,Zhenghai Wang,Xingjian Wang,Yingdong Ou,Mengqiang Cai,Zhixu Wu,Rongxin Tang,Yong Xia,Yuhao Wang,Hui Deng
Photodetectors (PDs) are critical parts of visible light communication (VLC) systems for achieving efficient photoelectronic conversion and high-fidelity transmission of signals. Antimony sulfide (Sb2S3) as a nontoxic, high optical absorption coefficient, and low-cost semiconductor becomes a promising candidate for applications in VLC systems. Particularly, Sb2S3 PDs were verified to have significantly weak light detection ability in the visible region. However, the response speed of Sb2S3 PDs with existing device structures is still relatively slow. Herein, through optimizing the device structure for the p–i–n type PDs, a p-type Sb2Se3 hole transport layer (HTL) is designed to enhance the built-in electric field and to accelerate the migration of photogenerated carriers for the high responsivity and fast response speed. The optimal thickness of the structure is obtained through the simulation of SCAPS-1D software, and the optimized devices show high-performance parameters, including a responsivity of 0.34 A W–1, a specific detectivity (D*) of 2.20 × 1012 Jones, the −3 dB bandwidth of 440 kHz, high stability, and the value of the Sb2S3 PDs can reach 60% in the range of 360–600 nm, which indicates that the device is very suitable for working in the visible light band. In addition, the resulting Sb2S3 PD is successfully integrated into VLC systems by designing a matched light detection circuit. The results suggest that the Sb2S3 PDs are expected to provide an alternative to future VLC system applications.
研究领域:
光电子学
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光子学
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半导体器件
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可见光通信
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薄膜光电探测器
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Wenhao Lyu,Tiantian Ma,Yu Yan,Congyu Zhang,Jiale Chao,Linyu Cong,Wei Zhou,Bo Fu
Metal nanomaterials possess excellent physical properties, which can be used as catalysts, storage carriers, and nonlinear photonic devices. Nickel nanoparticles have become increasingly crucial for ultrafast applications due to their broadband saturable absorption properties. Herein, nickel nanoparticles are prepared through an oil-phase method, followed by integration with nitrocellulose to form a composite film. Microscopic images, linear transmission, and nonlinear absorption properties of the film are presented to investigate the characteristics of nickel nanoparticles. Furthermore, Yb-, Er-, and Tm-doped fiber lasers are built based on a nickel-based saturable absorber, where Q-switched pulses are realized at 1, 1.5, and 2 μm. These results prove that nickel nanoparticles exhibit broad-band saturable absorption, showing promise for facilitating high-performance pulsed lasers.
研究领域:
纳米材料
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光子学
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激光技术
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非线性光学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Lu-Yu Cao,Shuai-Chen Si,Jin-Bo Yu,Chong-Geng Ma,Jian-Bei Qiu,Jing Wang
Optical ions doped transparent glasses have attracted more and more attention because of their potential application in photonic applications. Unfortunately, optically active dopants occupy at non-crystalline coordination environment, which leads to their poor luminescence efficiency. Therefore, how to enhance luminescence efficiency of optically active dopants in glasses remains a great challenge. Here, we proposed a precisely space-separated strategy of donor-acceptor and successfully developed an intense red emitting composite borosilicate glass co-doped with CsPbCl 3 quantum dots and Mn 2+ ions. By rationally controlling post heat-treatment, CsPbCl 3 QDs acting as donor were uniformly precipitated in glass and Mn 2+ ions acting as acceptor are close to CsPbCl 3 QDs but not inside CsPbCl 3 QDs. Benefitted from high absorption efficiency of CsPbCl 3 QDs and efficient energy transfer from CsPbCl 3 QDs to Mn 2+ ions in glasses, Mn 2+ ions give an intense red broadband emission at 650 nm, 11 times as intense as the one without CsPbCl 3 QDs. The optimal external quantum yield of the as-synthesized composite borosilicate glass is estimated to be 28.5%, 9.5 times as large as 3% for the one without CsPbCl 3 QDs. The precise space-separation and energy transfer rate dependent non-radiative energy coupling mechanism was reasonably proposed to explain how CsPbCl 3 QDs highly absorb energy, efficiently transfer it and finally feeding Mn 2+ ion. These results demonstrate that the strategy of using microcrystalline with high absorption efficiency as donor, for instance, CsPbX 3 QDs, to pump optical activator ions as acceptor, for instance, Mn 2+ ion in glass may be very promising for developing high luminescent performance ions-doped transparent glasses.
研究领域:
光子学
·
材料科学
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光学材料
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发光材料
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量子点
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能量传递
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Yi Zhang,Zhexuan Gao,Yingguang Li,Shuyang Chen,Mingxiao Han,Jie Li,Qihao Zhang,Yang Shen,Degang Deng,Shiqing Xu
The La2LiSbO6: xCr3+ phosphors were synthesized by means of a high-temperature solid-phase method. Based on the differences in ionic radius, valence state, and formation energy, the substitution sites of Cr3+ ions are discussed in detail. The optimized doping concentration of Cr3+ is determined to be 0.01. Under 517 nm excitation, the La2LiSbO6: 0.01Cr3+ phosphor presents a wide emission band (from 700 to 1350 nm) with a peak centered at 952 nm. Additionally, its corresponding full width at half-maximum is 155 nm, and the internal quantum efficiency reaches 62.4%. Meanwhile, the emission intensity of the La2LiSbO6: 0.01Cr3+ phosphor at 373 K is about 63.7% of that at room temperature, exhibiting good thermal stability. Aiming to fabricate a near-infrared phosphor-converted light-emitting diode device, the La2LiSbO6: 0.01Cr3+ phosphor is mixed with epoxy adhesive and cured on a green light-emitting diode chip. Under the irradiation of the fabricated light-emitting diode device, fruits and writing in the dark environment can be captured by a near-infrared camera. Hence, the La2LiSbO6: 0.01Cr3+ phosphor is promising for night vision.
研究领域:
材料科学
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光学材料
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固态照明
·
光子学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Yongbo Zhou,Ye Tian,Arfan Bukhtiar,Zhijie Zhou,Hualin Zhao,Wenchao Lin,Xianci Zhong,Bingsuo Zou
Among a II–VI semiconductor, ZnTe is an inherent p-type semiconductor and exhibits strong emissions within the visible range, which make it suitable for various optoelectronic applications. Here, we have obtained the ZnTe- and Fe-doped ZnTe microbelt by CVD growth. Near-infrared (NIR) luminescence from 600 to 1000 nm can be seen in the PL emission spectra of ZnTe microstructure excited by CW laser, along with the appearance of multimode peaks because of the optical microcavity. The NIR luminescence in ZnTe comes from the presence of Zn vacancies due to polymorphous transition of ZnTe in the vapor solid mechanism. The PL emission under femtosecond pulsed laser excitation produces a low-threshold laser line which is near the band edge of the ZnTe microbelt, which is quite different from the continuous wave excitation PL spectrum. The time of photon–matter interaction and the fast and slow coherent recombination of exciton and defect states determine their emission distribution. As the excitation pulse changes, the different optical behaviors generated by the semiconductor may be applied in many photonic devices. We also found that in addition to the two sides of the microbelt that form the FP cavity in the pure ZnTe microbelt, the interface in the doped ZnTe microbelt can also form the FP cavity together with one side of the microbelt; the presence of interface is due to the presence of impurities.
研究领域:
光电子学
·
半导体物理
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光子学
·
材料科学
·
纳米光子学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Endale T. Basore,Misgana U. Dumesso,Xiaofeng Liu,Jianrong Qiu
Transition metal ions are exceptional emitters of broadband near-infrared (near-IR) luminescence, enabling various applications in photonics and optics; however, their weak absorption and excitation bands often limit conversion performance. Among potential sensitizers, Cr3+ stands out, allowing the excitation of Ni2+ with broadband visible-near-IR light while preserving luminescence properties. Nevertheless, concentration-induced quenching in doped luminescent solids fundamentally undermines brightness due to a trade-off between internal quantum efficiency and excitation energy dynamics. In this study, we demonstrate unprecedented brightness in the broadband near-IR photoluminescence (PL) of the Cr3+–Ni2+ system, where single, heavily doped Cr3+ exhibits minimal PL, and tuning Ni2+ concentration offsets the competitive relationship between the light emitter and quencher. By coupling InGaN light-emitting diodes (LEDs) with an ultrabroadband near-IR PL phosphor, we achieve phosphor-converted LEDs with a record output power of 41.5 mW at 100 mA and a photoelectric efficiency of 19.53% at 20 mA, nearly doubling previous reports. Our findings unveil intrinsic suppression of concentration quenching and eliminate competing energy sinks by emphasizing the dominant role of emitters in downshifting excitation energies, thus opening new avenues for the design of bright, sensitized luminescent materials.
研究领域:
光子学
·
光学材料
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固态照明
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发光材料
·
近红外发射
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2015
·
IF 4.772
Lili Wang,Hyeon Mi Noh,Byung Kee Moon,Sung Heum Park,Kwang Ho Kim,Jinsheng Shi,Jung Hyun Jeong
Dual-mode excitation properties were introduced in Sm3+ doped Sr2CaMoO6 prepared by a high temperature solid state reaction technique. Two ways are available to generate white light in the single-component phosphor activated by Sm3+ ions. Warm white light can be obtained from Sr1.995Sm0.005CaMoO6 phosphor pumped by 380 or 411 nm excitation energy. The full visible spectral emission of the single-phase phosphor comes from the high and low level emission lines of Sm3+ ions as well as the intrinsic luminescence of MoO6 group. It is also competitive as yellow-emitting phosphor for blue pumped white LEDs and gives three emission bands at 567, 603, and 650 nm, presenting yellow luminescence upon 466 nm radiation. The 650 nm red emission band corresponding to 4G5/2 → 6H9/2 transition of Sm3+ can make its color rendering index better. The excellent photoluminescence of Sr2CaMoO6 is related to the partial tilting CaO6 octahedral and the lowered symmetry were confirmed by General Structure Analysis System. Band gap of Sr2CaMoO6 estimated from the diffuse reflection spectra and also calculated by CASTEP mode shows its semiconducting character. All the results show that the Sr2–xSmxCaMoO6 phosphors have considerable potential for applications in near UV LED or pumped by blue LED chip.
研究领域:
材料科学
·
光学材料
·
光子学
·
固态化学
·
发光材料
·
LED技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）