Tuning white upconversion emission in GdPO4:Er/Yb/Tm phosphors

Hassairi, M.; Garrido-Hernández, Aristeo; Dammak, M.; Zambón, Daniel; Chadeyron, G.; Mahiou, Rachid

doi:10.1016/j.jlumin.2018.07.024

Cited by 30 publications

(8 citation statements)

References 44 publications

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“…Lanthanide ions generally have large Stokes’ shifts, narrow emission bands, long excited state lifetimes, and high color purity emissions in the Visible‐IR region, which form the basis for extensive applications in white LEDs, sensors, lasers, up‐conversion emission, optical data storage, communications, medicine, etc . The color of the luminescence is determined primarily by the lanthanide ion, but optical spectra are also closely related to its local symmetry with the emission quantum efficiency being strongly related to the phonon energy of the host matrix.…”

Section: Introductionmentioning

confidence: 99%

Preparation and optical properties of samaria‐doped yttria‐stabilized zirconia single crystals

Tan

Wang

et al. 2019

J Am Ceram Soc

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Single crystals of yttria‐stabilized zirconia (YSZ) doped with various concentrations of Sm2O3 were synthesized by the optical floating zone method, and their structure and spectroscopic properties characterized using powder X‐ray diffraction (XRD), optical absorption, and luminescence measurements. XRD showed that the cubic phase of ZrO2 was stabilized by addition of Y2O3 and a series of absorption peaks characteristic of Sm3+ was detected by UV‐visible absorption spectroscopy. Three phenomenological J‐O oscillator strength parameters Ωt (t = 2, 4, 6) were calculated to evaluate the local structure and bonding in the vicinity of the Sm3+ for the 0.75 mol% Sm2O3: YSZ sample. These were in order of Ω2 < Ω4 < Ω6 with values of Ω2 = 5.46 × 10−20 cm2, Ω4 = 10.70 × 10−20 cm2, and Ω6 = 12.67 × 10−20 cm2, and indicate a relatively high symmetry and low covalent character for the Sm‐O bond at the Sm3+ sites in the YSZ matrix. Photoluminescence spectra recorded under an excitation of 404 nm showed four emission bands centered at 571 nm, 621 nm, 652 nm, and 716 nm corresponding to the transitions 4G5/2→6Hj (j = 5/2, 7/2, 9/2, 11/2). The transition probability, lifetime, and branching ratio obtained from the emission spectrum of the 0.75 mol% Sm2O3: YSZ crystal showed that YSZ is a potential host for Sm3+ to achieve a reddish‐orange laser output, and the Sm3+‐modified YSZ crystals have a possible use in reddish‐orange laser and lighting devices.

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Section: Introductionmentioning

confidence: 99%

Preparation and optical properties of samaria‐doped yttria‐stabilized zirconia single crystals

Tan

Wang

et al. 2019

J Am Ceram Soc

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“…Liutel 等人 [10] 通过在单个 CaMoO 4 基质中掺杂多个稀土离子以实现色彩调谐，表明 Tm 3+ 、Er 3+ 、Ho 3+ 的离子组合及其掺杂浓度对上转换发光颜色具有重要影响。 Wu 等人 [12] 制备了 NaYbF 4 : Er 3+ @NaYbF 4 : Tm 3+ @NaYF 4 核壳结构，发现当激发功率为 20.9W/cm 2 时，该结构呈现出暖白色发光，并表明其在适当的功率密度变化下能够实现颜色可调输出。Wang 等人 [13] 通过改变 Tm 3+ 和 Dy 3+ 离子共掺杂的 LiNbO 3 (Tm:Dy:CLN)单晶中稀土离子浓度，获得了白光发射，并在 20-430K 温度范围内得到最佳白光发射温度为 400K。然而，对于氟化物晶体中共掺杂 Yb 3+ /RE 3+ /Tm 3+ (RE 3+ =Ho 3+ , Er 3+ )的研究仍大多集中在对上转换红光，绿光和蓝光发射的有效调控，且在三掺杂氟化物微米晶体中通过单波长激发产生宽范围的彩色输出和上转换白光发射的研究报告相对较少。氟化物材料由于声子能量较低，可有效地降低材料无辐射几率，成为目前上转换发光效率较高的基质材料之一，如六方相的 NaYF 4 、NaLuF 4 等氟化物材料 [14,15] 。同时，其表现出较高的热稳定性及环境稳定性有助于在荧光显示、温度传感等领域进一步应用。近期，Zhang 等人 [16] 通过改变掺杂离子的浓度，在 NaYF 4 : 20%Yb 3+ /1%Ho 3+ /1%Tm 3+ 微米晶体中实现了白光发射。Pathak 等人 [17] 在 Eu/Yb 共掺杂的 NaYF 4 结构中，通过改变 Yb 3+ 离子浓度分析其对样品结构、形貌和发光性能的影响，在高 Yb 3+ 离子浓度条件下获得了白光发射，其可用于温度传感检测应用。除此之外，上转换白光发射在光电器件及显示等领域具有巨大应用前景，特别是在低功率激发下获取高亮的白光发射 [18] 。为此，进一步获得高强度上转换白光发射已成为大家面临的巨大挑战。如 Ye 课题组 [19] 在纳米尺度下对共掺体系进行惰性壳层的包覆，减少了由于非辐射跃迁引起的发光猝灭，实现了白光发射增强。 Song 等人 [20] 通过离子分掺的方式制备了 NaYF 4 : Yb 3+ /Er 3+ @NaYF 4 : Yb 3+ /Tm 3+ 核壳微米晶体，同样实现了白光发射。Liu 等人 [21] 根据 β-NaYF 4 ：Yb 3+ /Er 3+ @β-NaYF 4 ：Yb 3+ /Tm 3+ 的发射特性及温敏特性，在室温条件下获得了上转换白光发射，并表明该多功能核壳结构微晶在 WLED、防伪领域和温度传感领域具有潜在应用前景。同时，在本课题组前期工作中，通过对单颗粒微米棒发光特性的研究，发现构建微米核壳结构可以有效实现微米晶体上转换发射增强及调控 [22] 同时 Tm 3+ 离子 1 D 2 → 3 F 4 (450 nm)能级辐射跃迁具有微弱的蓝光发射 [27,28] 。由附录 ( 1 G 4 (Tm 3+ )+ 5 I 8 (Ho 3+ )→ 3 F 4 (Tm 3+ )+ 5 F 5 (Ho 3+ )，CR1)过程，进而有利于增强红光发射 [33] ，如图 7(a) 所示。同时， Ho 3+ 离子自身能级间交叉驰豫…”

Section: 引言unclassified

Upconversion white-light emission luminescence characteristics based on single-particle NaYF4 microrod

Gao¹,

Shao²,

Han³

et al. 2023

Acta Phys. Sin.

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White upconversion (UC) luminescent materials have shown incomparable advantages over other light sources in the fields of solid-state lighting, liquid crystal display and bioimaging, which has attracted extensive attention from researchers. In this work, a series of microcrystals doped with different ion concentrations were synthesized by hydrothermal method, such as NaYF4: Yb3+/Ho3+/Tm3+ and NaYF4: Yb3+/Ho3+/Tm3+, and their corresponding micron core-shell (CS) structures were constructed based on epitaxial growth technology. The structure and morphology of the prepared microcrystals were characterised by X-ray diffractometer (XRD) and scanning electron microscope (SEM), which showed that the microcrystals had a pure hexagonal-phase crystal structure with a rod-like shape. Under the excitation of 980 nm near infrared laser, the white UC luminescence characteristics of Ho3+/Tm3+ and Er3+/Tm3+ co-doped single-particle NaYF4 microcrystals were systematically studied by modulating the concentration of the doping ions. The study shows that in Ho3+/Tm3+ co-doped NaYF4 microcrystals, white UC luminescence can be easily achieved by modulating the concentration of Yb3+ ions, while in the Er3+/Tm3+ co-doped NaYF4 microcrystal, white UC luminescence can be effectively achieved by modulating the concentration of Er3+ion. According to the luminescence characteristics of the microncrystals in different doping systems, the physical mechanism of white light emission regulation is revealed, which is mainly due to the interaction between the doped ions, including cross relaxation (CR) processes and energy back transfer (EBT) processes. Meanwhile, an effective enhancement of the white UC luminescence on CS microrod was achieved by coating the NaYF4 inert shell. Therefore, ion doping technique and the construction of CS structure can not only realize the white UC luminescence of microrods, but also provide important experimental reference for further enhancing the luminescence characteristics of microrods, and expand the applications of microcrystals in the fields of display, optoelectronics and anti-counterfeiting.

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“…The 4 F 7/2 excited state decays to the 2 H 11/2 , 4 S 3/2 , and 4 F 9/2 states by nonradiative relaxation, and these then decay to the ground state, with green (544 and 560 nm) and red (654 and 678 nm) emissions that correspond to the 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , and 4 F 9/2 → 4 I 15/2 transitions, respectively. [37][38][39]…”

Section: Mechanisms For Energy Transfer Between Yb 3+ and Er 3+mentioning

confidence: 99%

Upconversion Emission in Tm/Er/Yb Co‐Doped Yttria Stabilized Zirconia Single Crystals

Pan

et al. 2022

Crystal Research and Technology

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Blue, green, and red emissions through upconversion and energy transfer processes are investigated as a function of the Tm3+ concentration in Tm/Er/Yb triply doped yttria stabilized zirconia (YSZ) crystals upon excitation at 980 nm. YSZ doped with 0.075–0.250 mol% Tm2O3, 1.50 mol% Er2O3, and 2.00 mol% Yb2O3 are prepared by the optical floating zone method, and confirmed to be in the cubic phase by X‐ray diffraction. The blue emission corresponds to the Tm3+ 1G4→3H6 transition, and is produced through a three‐photon process, whereas the green and red light are emitted through two‐photon processes from the Er3+ 2H11/2→4I15/2 and 4S3/2→4I15/2 transitions for green and the Er3+ 4F9/2→4I15/2 transition for red. However, interactions between the different lanthanide ions is a factor in determining the overall color of these triply doped crystals, and this is not simply a summation of the results from the singly doped systems, so this mechanism of energy transfer is discussed in detail. The CIE color chromaticity coordinates for the present samples under excitation at 980 nm approach (0.39, 0.55), which is in the yellow‐green region.

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Tuning white upconversion emission in GdPO4:Er/Yb/Tm phosphors

Cited by 30 publications

References 44 publications

Preparation and optical properties of samaria‐doped yttria‐stabilized zirconia single crystals

Preparation and optical properties of samaria‐doped yttria‐stabilized zirconia single crystals

Upconversion white-light emission luminescence characteristics based on single-particle NaYF<sub>4 </sub>microrod

Upconversion Emission in Tm/Er/Yb Co‐Doped Yttria Stabilized Zirconia Single Crystals

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