Untypical tuneable emission activated by NIR radiation observed in gadolinium borate nanomaterials doped with Yb 3+ , Ho 3+ and Ce 3+ ions

doi:10.21203/rs.3.rs-4307859/v1

Download PDF

Article

Untypical tuneable emission activated by NIR radiation observed in gadolinium borate nanomaterials doped with Yb 3+ , Ho 3+ and Ce 3+ ions

https://doi.org/10.21203/rs.3.rs-4307859/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 11 Nov, 2024

Read the published version in Scientific Reports →

You are reading this latest preprint version

New luminescent nanoparticles with adjustable emission properties were synthesized via a hydrothermal method to investigate the effect of Ce³⁺ concentration on the tuneable emission properties of Yb³⁺/Ho³⁺ co-doped gadolinium borates. The synthesized samples' comprehensive structural and morphological analysis was conducted utilizing X-ray diffraction and transmission electron microscopy. To obtain highly crystalline nanoparticles GdBO₃:Yb³⁺/Ho³⁺/Ce³⁺ characterized by intense and bright emission, they were annealed at 525°C and 925°C. Under the excitation of 972 nm, the tunable yellow to green up-conversion emission was observed, while the Ce³⁺ concentration increased. This change correlated with a difference in the correlated color temperature from 4345K to 5442K, respectively. The untypical changes observed in the red-to-green (R/G) ratio, displaying a declining trend contrary to conventional expectations, allowed for the proposed mechanism for understanding their UC luminescence properties. The results obtained indicate that the Ce³⁺ doped GdBO₃:Yb³⁺/Ho³⁺ nanoparticles demonstrate high application potential for anti-counterfeiting.

Physical sciences/Chemistry

Physical sciences/Chemistry/Chemical engineering

Physical sciences/Chemistry/Materials chemistry

Physical sciences/Materials science/Nanoscale materials

tunable up-conversion

luminescence

hydrothermal method

borates

nanomaterials

These days, up-converting materials are broadly studied due to their exceptional spectroscopic properties, enabling them to absorb two or more low-energy photons and emit one high-energy photon¹. This phenomenon finds numerous applications: solar cells^2–3, biomedicine⁴, optical imaging⁵, photonic devices^6,7, thermometric materials⁸ and anticounterfeiting^9,10. The up-conversion process can be performed using different mechanisms, which vary depending on the combinations of dopant ions and their electronic structure. The energy transfer up-conversion mechanism (ETU) is confirmed for various dopant ion systems, such as Yb³⁺/Er^{3+ 11–16}, Yb³⁺/Ho^{3+ 17,18}or Yb³⁺/Tm^{3+ 19–20}. Also, ETU is assigned to emission for the dopant ions system, where Yb³⁺ ions act as sensitizers and Ho³⁺ ions play the role of emitting ions ¹. Various combinations of dopant ions and matrices are synthesized to achieve luminescent nanoparticles with distinct emission colors, often dictated by the intended application of the resulting materials. Among the lanthanide ions (Ln³⁺), Ho³⁺ possess one of the more complex energy level structure, a long excited state lifetime and exhibit intense emission in both green and red regions^9,17. Therefore, they are often chosen as activators in up-conversion (UC) material studies. However, the low UC efficiency indicated by the single doping of Ho³⁺ necessitates sensitization. For this purpose, Yb³⁺ ions were chosen as sensitizers to enhance energy transfer efficiency^{18, 21}. Besides utilizing two different Ln³⁺ ions for color tuning, another effective method for color tuning can be employed in UC systems. It is implementing additional Ce³⁺ ions, allowing for changes depending on the concentration, without altering the composition of the materials. The 4f configuration of Ce³⁺ ions comprises solely two distinct energy levels, namely ²F_5/2 and ²F_7/2^22,23. By leveraging energy transfer between the energy levels, it becomes possible to enhance emission from certain levels while quenching emission from others, thereby altering the color of the overall emission.

Luminescent materials based on rare earth orthoborates REBO₃ (RE = Gd, Y, La, etc.) play an important role as an inorganic matrix for Ln³⁺ (Ln = Yb, Er, Tm, Ho, Ce, Eu, Tb, etc.) ^24,25. The REBO₃ matrices are ideal for doping by Ln³⁺ in a broad range of concentrations without forming any impurity phases and are chemically and thermally stable^26,27. Many various methods were used to synthesize borates-based nanomaterials, including solid-state²⁸, co-precipitation²⁹, sol-gel Pechini method³⁰, polyol³¹ or sol-gel drop-coating method², and also hydrothermal conditions³². Among them, the hydrothermal way of synthesis enables obtaining rare earth borate-based nanomaterials (RENMs) with exceptional structure and morphology, among others, unusual for another method³² Unlike solid-state or sol-gel reactions, hydrothermal conditions produce final nanomaterial without high-temperature annealing, only with drying. It avoids the overgrowth of crystallites, their sintering, and agglomeration.

The photoluminescence of Ce³⁺ in various inorganic phosphors is extensively studied, but no research is found related to the GdBO₃:Yb³⁺, Ho³⁺, Ce³⁺ materials^10,33,34. The ground state of Ce³⁺ is a doublet³⁵, and the lower excited states are associated with the 5d configuration. Owing to the doublet characteristics of the 4f, the emission from the ground state of Ce³⁺ exhibits two overlapping bands³⁶. Due to the distinctive energy level structure of Ce³⁺ ions, the co-doping of Ce³⁺ ions with Ho³⁺ ions results in multiple cross-relaxation processes. This doping strategy effectively enables tuning the up-conversion luminescence process of Ho³⁺ ions from green emission into the red color direction³³. Our research delves into the unconventional tuning of color emission in phosphors utilizing Ce³⁺ within orthoborate matrices. This tuning is achieved through doping with Yb³⁺ and Ho³⁺ activated by NIR radiation. However, it is noteworthy that there is a lack of appropriate studies on this aspect based on our current knowledge.

Apparatus. Thermogravimetric analysis (TG) and differential thermal gravimetry (DTA) were obtained using the Haas DSC XP-10i. X-ray diffraction patterns (XRD) were measured by a Bruker AXS D8 Advance diffractometer in Debye–Scherrer geometry, with CuKα1 radiation (1.541874 Å) in the 2θ ranges from 6–60º. Each sample composition was estimated based on ICP-MS analysis using the NEXION 300D Perkin Elmer spectrometer. The excitation and emission spectra of the nanoparticles produced were measured by applying a QuantaMasterTM 40 spectrophotometer equipped with an Opolette 355LD UVDM tunable laser, which had a repetition rate of 20 Hz, as the excitation source and a Hamamatsu R928 photomultiplier as the detector. Excitation and emission spectra were corrected for the instrumental response. The TEM images were recorded at FEI Tecnai G2 20 X-TWIN transmission electron microscope at an accelerating voltage of 200 kV.

Synthesis. A series of GdBO₃-doped nanomaterials was prepared under hydrothermal conditions in a Berghof DAB-2 reactor. The synthesis was continued for 20 h at temperature T = 200°C. The GdBO₃ matrix was doped intentionally with 18% Yb³⁺,1%Ho³⁺ and x% Ce³⁺ ions (x = 0; 1; 6; 10; 20). The real concentrations of particular ions were established as x = 0, 0.1, 0.15, 6.5, 13 (Supplementary Table S1) based on ICP-MS analysis, respectively. The explanation of the phenomenon is performed in the results section. The starting materials Gd₂O₃, Yb₂O_3, and Ho₂O₃ (Stanford Materials, 99.99%) were dissolved in concentrated hydrochloric acid (POCh S.A., ultrapure). As prepared solutions of the GdCl₃, YbCl₃ and HoCl₃ were diluted with distilled water, to obtain 0.5 M solutions. The solutions were evaporated three times to remove the excess of the acid. The Ce³⁺ ions were introduced as CeCl₃ (Stanford Materials, 99.99%) 0.5 M water solution. The stoichiometric amounts of the appropriate chloride solutions, according to the formula Gd_1 − xYb_0.18Ho_0.01Ce_xBO₃ with x = 0, 0.1, 0.15, 6.5, 13) and a 0.5 M solution of H₃BO₃ (REACHIM, 99%) in 100% excess, added dropwise under vigorous stirring, were mixed. Finally, distilled water was added to the above mixture to reach ∼30 mL for the total volume, and the pH was adjusted to ∼5.6 using an NH_3(aq) solution. The as-prepared transparent solutions were placed in Teflon vessels, put in an autoclave, and isothermally heated at 200°C for 20 h. After synthesis, the reactor self-cooled down to room temperature. The synthesized products were collected by centrifugation and washed several times with ethanol. The as-obtained white powders were divided into three parts to dry at 80°C/8 h, anneal at 525°C/3 h, and 925°C/3 h in air, and then were grounded in a mortar and analyzed. The hydrothermal synthesis scheme is shown in Supplementary Fig. S1.

The hydrothermal method and properly selected synthesis conditions enable obtaining nanoparticles (NPs) composed of GdBO₃ doped with 18%Yb³⁺, 1%Ho³⁺, and various concentrations of Ce³⁺ ions. The desired structure of the NPs was obtained in situ under hydrothermal conditions, and it was unnecessary to calcinate the product to achieve the desired monoclinic structure of NPs or precipitate the precursor before the hydrothermal reaction, as often suggested in the literature ³⁷. The as-precipitated product was dried at 80°C for 24 hours. However, to enhance the NPs' crystallinity and simultaneously achieve a more intense emission, samples were annealed at 525°C and 925°C. The calcination temperature was estimated based on TGA analysis (Fig. 1) and also literature reports. At about 525°C, borates start to transform into stable high-temperature forms, and 925°C is the point at which the most stable form of borates is expected ³¹.

The ICP-MS analysis revealed disparities in the actual concentrations of Ce³⁺ ions and partially of Yb³⁺ ions within the prepared NPs compared to the intended values (Supplementary Table S1). The reaction conditions were identical; hence, the ultimate product composition was influenced by additional factors. This discrepancy could stem from variations in the ionic radii among Ln³⁺ ions and the solubilities of RE-borates ^38–40. Specifically, the comparatively lower solubility of GdBO₃, YbBO₃, and HoBO₃ (precipitating faster than CeBO₃) may contribute to the significantly reduced concentration of Ce³⁺ ions in the resultant materials, diverging from the anticipated levels based on the quantities of reagent salts added. Furthermore, the larger ionic radii of Ce³⁺ ions compared to the other Ln³⁺ ions (Gd, Yb, Ho) impede the effective exchange of Gd³⁺ ions within the matrix.

Although Ce³⁺ and Ho³⁺ ions possess the most similar ionic radii, a surplus of Ce³⁺ ions is necessary to incorporate them into the gadolinium borate structure. While RE-based compounds are typically isostructural, deviations from this trend frequently manifest at the gadolinium stage⁴¹. Consequently, borates featuring Gd, Yb, and Ho are more favorable than those incorporating Ce. The XRD patterns of the GdBO₃-doped NPs match well with reference pattern COD 7018841³⁰ and the crystal structure was identified as monoclinic C2/c (Fig. 2a, b). No other phases or impurities were detected, consistent with the basic parameters of GdBO₃. The only observed changes were that, with increased calcination temperature, the XRD lines became more intense, sharp, and narrow. This corresponds to higher crystallinity and a larger average grain size of the product. In addition, the intensities of diffraction lines positioned at approximately 20° and 27° exhibited exceptional increase relative to other diffraction lines. They displayed significantly greater intensity than the same XRD lines observed on patterns for samples subjected to those dried at 80°C. This phenomenon may be attributable to preferential

crystal growth along one or two specific crystallographic axes. This observation aligns with TEM images, which depict a nearly two-dimensional morphology of the NPs, characterized by a flattened plate-like structure (Fig. 3)⁴². The monoclinic structure of the NPs, which is schematically performed in Fig. 2b, confirms that eight neighboring atoms surround two gadolinium ions. Furthermore, the boron atoms are 4-coordinated in tetrahedral BO₄ groups, which form three-membered rings comprising polyborate B₃O₉⁹⁻ units. The coordinating oxygens are divided into two types: terminal oxygens form a trigonal antiprism around Gd³⁺ ions while bridging oxygens connect the cations ³⁰. Then, the TEM images of the GdBO₃ doped with 18%Yb³⁺, 1%Ho³⁺, and 0.15%Ce³⁺ (Fig. 3) unveil noticeable variations in the average grain size and morphology of the NPs under different temperature treatments. Specifically, drying at 80°C followed by annealing at 525°C and 925°C results in distinct product characteristics. The dried samples present the most irregular morphology. They consist of two phases: bigger particles and a significant amount of very small particles, which look like nucleation seeds. A higher calcination temperature is needed for a more crystalline and homogenous product. The morphology is non-uniform for each NP but can be described as a thin flake. The average grain size of NPs dried at 80°C is ~ 70 nm, calcinated at 525°C is ~ 30 nm, and at 925°C is ~ 102 nm. The particles show noticeable agglomeration, a common occurrence in materials prepared by hydrothermal methods. However, the material's morphology is suitable for potential applications like anticounterfeiting tags and modifying paper or cellulose fibers.

Figure 4 presents the up-conversion spectra of GdBO₃:18%Yb³⁺/1%Ho³⁺/x%Ce³⁺ (x = 0; 0.1; 0.15; 6.5; 13) under NIR 972 nm excitation, showing dependency of the particular emission bands intensity on various Ce³⁺ concentration. It should be noted that neither ytterbium nor cerium ions have 4f levels corresponding to green and red emissions. The spectra consist mainly of both typical Ho³⁺ bands, namely ⁵S₂/⁵F₄ → ⁵I₈ in the green region at 537 nm and ⁵F₅ → ⁵I₈ in the red range, with the maximum at 647 nm. A band related to the transition ⁵F₄/⁵S₂ → ⁵I₇ at 753 nm can also be depicted. The emission spectra show that the intensity of the red and the green bands is comparable regarding each sample prepared. However, a more detailed analysis of the red-to-green band intensity ratio shows slight changes as the concentration of Ce³⁺ ions varies. Moreover, the influence of Ce³⁺ ions on overall luminescence intensity is decreasing, especially starting from the sample with higher Ce³⁺ concentration, namely 6.5%. The observed phenomenon stems from the energy transfer between Ho³⁺ and Ce³⁺ ions, which can affect the transition pathways within the emission of the prepared NPs^9,34. To investigate the dependency of the R/G ratio on Ce³⁺ ion doping, the area of the red and green band was determined and compared, which is presented accordingly in Fig. 4 (insert). The R/G intensity ratio of up-conversion emission spectra decreases from 1.8 to 0.62 with increasing concentration of cerium ions. Changes in color emission are observed as a shift from the yellow-green spectral region (for 0% Ce³⁺ concentration) towards the green region with an increase in Ce³⁺ concentration to 13%. In this study, the correlated color temperature (CCT) was calculated using the McCamy equation based on the CIE (1931 Commission Internationale de l’Eclairage) chromaticity coordinates, x, and y, while visualizing the color emission on chromaticity diagrams and schemes. The CCT was calculated by using the Eq. 4³:

$$\varvec{C}\varvec{C}\varvec{T}= -{437\varvec{n}}^{3}+{3601\varvec{n}}^{2 }-6861\varvec{n}+5514.31$$

$$\varvec{n}=\frac{(\varvec{x}- {\varvec{x}}_{\varvec{e}})}{(\varvec{y}- {\varvec{y}}_{\varvec{e}})}$$

where: x_e = 0.3320, y_e = 0.1858, and x and y are the color coordinates.

The results are presented in Fig. 5, where one can observe an increase in color temperature from 4345K to 5442K with the increase in Ce³⁺ concentration.

The unusual changes in the red-to-green (R/G) ratio, characterized by a decreasing trend contrary to the typical increase, prompted an investigation into the mechanism of UC processes. As the concentration of Ce³⁺ ions increases, the red and green emission bands continuously decrease, suggesting the involvement of ET between Ho³⁺ and Ce³⁺ ions. Specifically, the green emission arises from the population of the ⁵F₄ and ⁵S₂ states through two distinct ET pathways from Yb³⁺ to Ho³⁺ ions (ET1 and ET2, Fig. 6). However, the population of the red ⁵F₅ level necessitates nonradiative relaxation from ⁵F₄, ⁵S₂ to ⁵F₅, and ⁵I₆ to ⁵I₇, implying a longer time to obtain the red emission. The energy gap between the ²F_7/2 - ²F_5/2 levels of Ce³⁺ ions aligns well with the energy difference between ⁵I₆ - ⁵I₇ and ⁵F₄,⁵S₂-⁵F₅ levels of Ho³⁺ ions, facilitating the promotion of these energy levels and concurrent red emission. Nevertheless, the intensities of the green and red emission bands decrease with increasing Ce³⁺ concentration, indicating competition between ETs from Yb³⁺ to Ho³⁺ and back ET (bET) from Ho³⁺ to Yb³⁺. Upon establishing the optimal concentration of Yb³⁺ ions, ET transfer promotes red emission, while bET enhances green emission. In our samples, the transition towards the green region suggests that the enhancement of red emission by cross-relaxation (CR) from Ce³⁺ to Ho³⁺ ions and ET from Yb³⁺ to Ho³⁺ is outweighed by bET from Ho³⁺ to Yb³⁺.

Comparatively, in the case of samples performed in this article, inversely compared to the samples doped with Yb³⁺, Ho³⁺, and Ce³⁺ ions in a molybdate matrix ³⁴, there is an insufficient concentration of Yb³⁺ ions to populate the Ho³⁺ ions’ red emitting level, leading to the dominance of bET and resulting in green emission. With a higher concentration of Yb³⁺_, the color tends towards yellowish due to increased participation of the red color; however, decreased Yb³⁺ concentration, consistent ICP-MS results, leads to the dominance of bET mechanisms, rendering the Ho³⁺ red level inadequately pumped by Yb³⁺. Concurrently, CR processes from Ho³⁺ to Ce³⁺ quench the red emission as Ce³⁺ concentration increases. These processes collectively contribute to the atypical behavior of tunability, shifting the color from yellowish to green with increasing Ce³⁺ concentration in the samples prepared. The atypical red-to-green (R/G) ratio changes, indicating a decreasing trend contrary to the typical increase, prompted us to analyze the UC process mechanism. The emission bands decrease continuously, together with increasing concentration of Ce³⁺ ions. It indicates that the ET between Ho³⁺ and Ce³⁺ ions must be responsible. The ⁵F₄ and ⁵S₂ states are mainly populated by two different types of ET from Yb³⁺ to Ho³⁺ ions, what resulted in green emission. However, the population red ⁵F₅ level requires nonradiative relaxation from ⁵F₄, ⁵S₂ to ⁵F₅, and ⁵I₆ to ⁵I₇. It means that red emission is populated in a longer time. The energy gap between ²F_7/2 - ²F_5/2 of Ce³⁺ ions matches well with the energy between ⁵I₆ - ⁵I₇ and ⁵F₄,⁵S₂-⁵F₅ of Ho³⁺ ions, which can result in the promotion of these energy levels and at the same time the red emission. However, the emission intensity of the green and red emission bands decreases with increasing Ce³⁺ concentration, so the ET from Yb³⁺ to Ho³⁺ must compete with back ET from Ho³⁺ to Yb³⁺. When the optimal concentration of the Yb³⁺ ions in samples is established, the ET transfer can promote the red emission, and at the same time, BET enhances the green emission. Here, in the case of our samples, the color changes into green region suggest that the enhancement of red emission by ET from Ce³⁺ to Ho³⁺ and ET from Yb³⁺ to Ho³⁺ loses with BET from Ho³⁺ to Yb³⁺. Compared to the results observed for the molybdate matrix doped with Yb³⁺, Ho³⁺, and Ce³⁺, in our case, there are too few Yb³⁺ ions to populate the Ho red emitting level, and the BET dominates, resulting in green emission³⁴. When there is more Yb³⁺ - the color is more yellowish. Hence, the participation of the red color is higher, but when the Yb³⁺ decreases (which is in accordance with ICP-MS results), the BET mechanism wins and pumping by Yb³⁺, the Ho³⁺ of the red level is not sufficient. At the same time, the cross-relaxation processes (CR) from Ho³⁺ to Ce³⁺ quench the red emission while the Ce³⁺ concentration increases. All these processes result in untypical tunability behavior and shift from yellowish to green color with increased Ce³⁺ concentration in the performed samples.

Supplementary Fig. S2 performs excitation spectra with quite narrow bands with a maximum at 972 nm, which are assigned to the ²F_7/2 → ²F_5/2 transition, related to the energy absorption by Yb³⁺ ions. The narrow shape of the band is an effect of a low crystal field around Yb³⁺ ions, which is characteristic for this type of crystal borates structure⁴⁴. However, does the observation of the ²F_7/2 → ²F_5/2 transition band confirm the energy transfer from Yb³⁺ to Ho³⁺ ions leading to the emission in the visible range. Consequently, the intensities of excitation peaks are Ho³⁺/Ce³⁺/Yb³⁺ is changing adequately to the concentration of Ho³⁺/Ce³⁺/Yb³⁺, which is in agreement with the emission spectra shown.

In summary, we have successfully synthesized a series of crystalline nanoparticles GdBO₃:Yb³⁺/Ho³⁺/Ce³⁺ prepared by hydrothermal method. We reported untypical tuneable emission activated by NIR radiation, where excited at 972 nm, the intensity of the yellow-green upconversion emission demonstrated tunability to green emission with Ce³⁺ concentration increasing. The annealing process at different temperatures (525°C and 925°C) did not affect the crystal structure and was identified as monoclinic C2/c, indicating stability under thermal treatment. Nevertheless, it was observed that at higher annealing temperatures, the samples exhibited increased crystallinity. With an increase in the concentration of Ce³⁺ ion dopant, a color shift was observed from greenish-yellow towards green, along with a change in the correlated color temperature (CCT) from 4345K to 5442K, respectively. The results indicate that the obtained phosphors exhibit good up-conversion intensity, which can be easily tunable by using an appropriate concentration of Ce³⁺ ions. The untypical tuneable emission, activated by NIR radiation, presents promising opportunities for application across diverse fields, including anti-counterfeiting, optoelectronics, and display technologies.

Acknowledgements

The presented results were ﬁnancially supported by the National Centre for Research and Development, LIDER/39/0141/L-9/17/NCBR/2018.

Author contributions

A.Sz. – Conceptualization, Methodology, Funding acquisition, Supervision, Writing – original draft, Writing – review & editing; J. Cz. – Data curation, Writing – original draft, Validation, Visualization, Investigation.

Competing interests

There are no conflicts to declare.

Data availability

The authors declare that the data supporting the findings of this study are available within the paper and its Supplementary Information files. Should any raw data files be needed in another format they are available from the corresponding author upon reasonable request.

Auzel, F. Upconversion and Anti-Stokes Processes with f and d Ions in Solids. Chem. Rev. 104, 139–173 (2004).
Fang, D. et al. Application of bidirectional (up and down)-conversion luminescence material (GdBO₃:Yb³⁺/Tb³⁺) in CdSe_0.4S_0.6quantum dot-sensitized solar cells. Opt Mater (Amst) 88, 80–90 (2019).
Kumar, A. & Manam, J. Observation of up conversion/ down conversion luminescence and structural analysis of La₂Zr₂O₇: Pr³⁺ nano phosphors. Mater. Sci. Semicond. Process 148, 106828; 10.1016/j.mssp.2022.106828 (2022).
Peng, H., Li, S., Xing, J., Yang, F. & Wu, A. Surface plasmon resonance of Au/Ag metals for the photoluminescence enhancement of lanthanide ion Ln³⁺doped upconversion nanoparticles in bioimaging. J. Mater. Chem.B, 11, 5238; 10.1039/D2TB02251F (2023) .
Park, H. et al. Epitaxial KNbO₃:Yb³⁺,Er³⁺ nanopattern for enhanced upconversion photoluminescence. J. Alloys Compd. 813, 152238; 10.1016/j.jallcom.2019.152238 (2020).
Lee, G. et al. Upconversion nanomaterials and delivery systems for smart photonic medicines and healthcare devices. Adv. Drug Deliv. Rev. 188, 114419; 10.1016/j.addr.2022.114419 (2022).
Deng, R. et al. Temporal full-colour tuning through non-steady-state upconversion. Nat Nanotechnol. 10, 237–242 (2015).
Pang, T. & Wang, J. Controllable upconversion luminescence and temperature sensing behavior in NaGdF₄:Yb³⁺/Ho³⁺/Ce³⁺ nano-phosphors. Mater. Res. Express 5, 015049; 10.1088/2053-1591/aaa683 (2018).
Zhang, T. et al. Enhanced red emission of Yb, Ho: NaYGd(WO₄)₂ phosphors by codoping Ce³⁺. J. Lumin. 240, 118432; 10.1016/j.jlumin.2021.118432 (2021).
Xu, L., Zheng, H., Pang, T. & Mao, J. Multicolor luminescence of hexagonal NaYF₄:Yb³⁺/Ho³⁺/Ce³⁺ microcrystals with tunable morphology under 940 nm excitation for temperature-responsive anti-counterfeiting. J. Rare Earth. 40, 406–414 (2022).
Rivera-López, F., Torres, M. E. & Gil de Cos, G. Upconversion and cooperative luminescence in YBO₃:Yb³⁺- Er³⁺. Mater. Today Commun. 27, 102434; 10.1016/j.mtcomm.2021.102434 (2021).
Hegde, V. et al. Analysis of Optical and Near-Infrared Luminescence of Er³⁺ and Er³⁺/ Yb³⁺ Co-Doped Heavy Metal Borate Glasses for Optical Amplifier Applications. Photonics 9, 355; 10.3390/photonics9050355 (2022).
Yu, W. et al. Up-conversion luminescence of NaY(WO₄)₂: Yb, Er under 1550 and 980 nm excitation. Mater. Res. Bull. 80, 223–229 (2016).
Pinatti, I. M. et al. YVO₄:RE (RE = Eu, Tm, and Yb/Er) nanoparticles synthesized by the microwave-assisted hydrothermal method for photoluminescence application. Eclet. Quim. J. 47, 39–49 (2022).
Zhou, Y. et al. Laser-Induced Heating in GdVO₄: Yb³⁺/Er³⁺Nanocrystals for Thermometry. ACS Appl. Nano. Mater. 5, 16388–16401 (2022).
Kozhevnikova, N. M. Synthesis and Characterization of a KBaGd(MoO₄)₃:Er³⁺/Yb³⁺ Phosphor with a Scheelite-Like Structure. Inorg. Mater. 58, 371–378 (2022).
Hydrothermal synthesis and upconversion luminescence of NaGd(WO₄)₂ co-doped with Ho³⁺ and Yb³⁺. J. Lumin. 153, 1–4 (2014).
Ni, Z., Zhu, Y., Zhang, H. & Su, Y. Yb³⁺/Ho³⁺ doped Ba₃Y₂B₄O₁₂ phosphors: Upconversion luminescence and temperature sensing properties. J. Lumin. 268, 120427; 10.1016/j.jlumin.2023.120427 (2023).
Gao, D. et al. Codopant ion-induced tunable upconversion emission in β-NaYF₄: Yb³⁺/Tm³⁺ nanorods. Dalton Trans. 42, 1834–1841 (2013).
Zhang, Z. et al. Novel Tm³⁺/Yb³⁺-co-doped Bi₂MoO₆: Synthesis, characterization, and enhanced photocatalytic activity under visible-light irradiation. J. Mate.r Res. 35, 312–320 (2020).
Makumbane, V., Yagoub, M. Y. A., Xia, Z., Kroon, R. E. & Swart, H. C. Up-Conversion Luminescence and Optical Temperature Sensing Behaviour of Y₂O₃:Ho³⁺, Yb³⁺ Phosphors. Crystals (Basel) 13, 1288; 10.3390/cryst13081288 (2023).
Liu, X., Qiu, J., Xu, X. & Zhou, D. Effect of Ce³⁺concentration on the luminescence properties of Ce³⁺/Er³⁺/Yb³⁺ tri-doped NaYF₄ nanocrystals. J. Nanosci. Nanotechnol. 16, 3749–3753 (2016).
Tanner, P. A. Some misconceptions concerning the electronic spectra of tri-positive europium and cerium. Chem. Soc. Rev. 42, 5090–5101 (2013).
Yang, S. & Park, S. Self-Activating Strontium Orthoborate Blue Phosphors Induced by Cation and Anion Deficiencies and Their Rare-Earth-Free White Ultraviolet Light-Emitting Diodes. J. Phys. Chem. Lett. 13, 9766 – 9770 (2022).
Tawalare, P. K. Luminescent inorganic mixed borate phosphors materials for lighting, Luminescence. 37, 1226-1245 (2022).
Yu, Z., Yang, Y. & Sun, J. Narrow UVB-Emitted YBO₃ Phosphor Activated by Bi³⁺ and Gd³⁺ Co-Doping. Nanomaterials 13, 1013; 10.3390/nano13061013 (2023).
Beyaz, S., Bulbul, B., Tulek, R. & Teke, A. Synthesis and characterization of well-dispersed amorphous LnBO₃·3H₂O (Ln: Dy, Tb) nanoparticles. Chem. Pap. 74, 2449–2459 (2020).
Zhao, L., Cao, Z., Wei, X., Yin, M. & Chen, Y. Luminescence properties of Eu³⁺ doped YBO₃ for temperature sensing. J. Rare Earth. 35, 356–360 (2017).
Zhu, Q., Wang, S., Li, J. G., Li, X. & Sun, X. Spherical engineering and space-group dependent luminescence behavior of YBO₃:Eu³⁺ red phosphors. J. Alloys Compd.731, 1069–1079 (2018).
Szczeszak, A., Grzyb, T., Lis, S. & Wiglusz, R. J. Revision of structural properties of GdBO₃nanopowders doped with Eu³⁺ ions through spectroscopic studies. Dalton Trans.41, 5824–5831 (2012).
Nair, R. G., Nigam, S., Sudarsan, V., Vatsa, R. K. & Jain, V. K. YBO₃ versus Y₃BO₆host on Tb³⁺ luminescence. J. Lumin.195, 271–277 (2018).
Szczeszak, A. et al. Hydrothermal synthesis and structural and spectroscopic properties of the new triclinic form of GdBO₃:Eu³⁺ nanocrystals. Inorg. Chem.52, 4934–4940 (2013).
An, N. et al. Improved temperature sensing performance of YAG: Ho³⁺/Yb³⁺ by doping Ce³⁺ ions based on up-conversion luminescence. J. Alloys. Compd.843, 156057; 10.1016/j.jallcom.2020.156057 (2020).
Li, K. & Deun, R. Van. Low-Temperature Solid-State Synthesis and Upconversion Luminescence Properties in (Na/Li)Bi(MoO₄)₂:Yb³⁺,Er³⁺ and Color Tuning in (Na/Li)Bi(MoO₄)₂:Yb³⁺,Ho³⁺,Ce³⁺ Phosphors. Inorg. Chem.58, 6821–6831 (2019).
Isber, S., Gratens, X., Charar, S. & Golacki, Z. Magnetic properties of Ce³⁺ in PbCeA (A= Te, Se, S). in EPJ Web of Conferences, 40 (2013).
Oza, A., Ojha, V., Dhale, S. & Dhoble, S. Photoluminescence and thermoluminescence in Dy³⁺-, Ce³⁺-, and Tb³⁺-activated MgB₄O₇ phosphor for dosimetry application. Luminescence37, 1563–1574 (2022).
Lee, Y. S. & Lee, H. Structure and electrochemical behavior of LiMnBO₃ synthesized at various temperatures. Electron. Mater. Lett.10, 253–258 (2014).
Grzyb, T. & Przybylska, D. Formation Mechanism, Structural, and Upconversion Properties of Alkaline Rare-Earth Fluoride Nanocrystals Doped with Yb³⁺/Er³⁺ Ions. Inorg. Chem.57, 6410–6420 (2018).
Szczeszak, A., Grzyb, T., Nowaczyk, G. & Ekner-Grzyb, A. Emission colour changes in the CaF₂ sub-microspheres doped with Yb³⁺, Er³⁺ and Mn²⁺ ions. J. Alloys Compd. 817, 152718 10.1016/j.jallcom.2019.152718 (2020).
Rare Earth Separations by Selective Borate Crystallization. Lanthanides, Tantalum and Niobium (ed. Möller, P., Černý, P. & Saupé, F.) 10.1007/978-3-642-87262-4 (Springer Berlin Heidelberg, 1989).
Yin, X. et al. Rare earth separations by selective borate crystallization. Nat Commun8, 14438; 10.1038/ncomms14438 (2017).
Szczeszak, A., Jurga, N. & Lis, S. Effect of the Ce³⁺ ions co-doping on the emission color of the up-converting NaYbF₄ doped with Ho³⁺ ions. Ceram. Int.46, 26382–26387 (2020).
McCamy, C. S. Correlated color temperature as an explicit function of chromaticity coordinates. Color Res. Appl.17, 142–144 (1992).
Sokólska, I., Ryba-Romanowski, W., Gołab, S. & Łukasiewicz, T. The Optical Properties of Yb³⁺ Ions in LiTaO₃ :Nd,Yb Crystals. Appl. Phys. B.65, 495–498 (1997).

No competing interests reported.

Download PDF

Journal Publication

published 11 Nov, 2024

Read the published version in Scientific Reports →

Editorial decision: Revision requested
15 May, 2024
Reviews received at journal
08 May, 2024
Reviews received at journal
01 May, 2024
Reviewers agreed at journal
01 May, 2024
Reviewers agreed at journal
01 May, 2024
Reviewers invited by journal
01 May, 2024
Editor assigned by journal
27 Apr, 2024
Editor invited by journal
27 Apr, 2024
Submission checks completed at journal
27 Apr, 2024
First submitted to journal
22 Apr, 2024

You are reading this latest preprint version

Untypical tuneable emission activated by NIR radiation observed in gadolinium borate nanomaterials doped with Yb 3+ , Ho 3+ and Ce 3+ ions

Status:

Journal Publication

Version 1

Abstract

Figures

Introduction

Experimental section

Results and discussion

Conclusions

Declarations

References

Additional Declarations

Status:

Journal Publication

Version 1