Next Article in Journal
A Bi-Modulus Material Model for Bending Test on NHL3.5 Lime Mortar
Next Article in Special Issue
Recent Advances in Multi-Site Luminescent Materials: Design, Identification and Regulation
Previous Article in Journal
Superior Comprehensive Mechanical Properties of a Low-Carbon Medium Manganese Steel for Replacing AISI 4330 Steel in the Oil and Gas Industry
Previous Article in Special Issue
Achieving Persistent Luminescence Performance Based on the Cation-Tunable Trap Distribution
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Materials
Volume 16
Issue 2
10.3390/ma16020488
materials-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Eu3+-Doped (Gd, La)AlO3 Perovskite Single Crystals: Growth and Red-Emitting Luminescence

by
Tong Wu
1,2,
Qian Zhang
1,
Yun Shi
1,3,*,
Ling Wang
1,2,
Yifei Xiong
1,
Hui Wang
1,
Jinghong Fang
1,
Jinqi Ni
1,
Huan He
1,
Zhenzhen Zhou
1,
Qian Liu
1 and
Jianding Yu
1,3
1
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
2
College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China
3
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
*
Author to whom correspondence should be addressed.
Materials 2023, 16(2), 488; https://doi.org/10.3390/ma16020488
Submission received: 30 October 2022 / Revised: 18 December 2022 / Accepted: 29 December 2022 / Published: 4 January 2023
(This article belongs to the Special Issue Recent Advances in Rare Earth Luminescent Materials)
Browse Figures
Review Reports Versions Notes

Abstract

:
Eu3+-doped GdAlO3 (Eu:GAP) and Gd0.5La0.5AlO3 (Eu:GLAP) perovskite single crystals were successfully grown using the optical floating zone (OFZ) method. The microstructure, optical, photoluminescence (PL) and radioluminescence (under X-ray excitation, XEL) were investigated. Under the PL excitation of 275 nm, obvious emission bands peaking at 556 nm, 592 nm, 617 nm, 625 nm, 655 nm, and 706 nm were demonstrated, which correspond to the 5D0 → 7Fj (j = 0–4) transitions of Eu3+. The grown Eu:GAP single crystal showed a stronger PL intensity compared with that of Eu:GLAP in the red light region. After annealing at 1000 °C for 4 h in weak reductive atmosphere (Ar + 5% H2), a slight redshift and dramatic enhancement of PL and XEL intensity occurred. In addition, Eu:GLAP show a more intense XEL emission than that of Eu:GAP. Considering their different densities, these two kinds of red luminescence phosphors are proposed to be promising in a wide field of X-ray imaging, warm white, or plant lighting, respectively.

1. Introduction

Rare earth perovskite oxides (REMO3; RE = Y, La, Lu; M is metal) have demonstrated their advantages in the fields of electricity, magnetism, and photocatalysis, etc. [1,2,3], while rare earth aluminate perovskites (REAlO3) are relatively promising as a luminescence host [4]. In REAlO3, the lattice position of RE is surrounded by twelve O2− anions and can be replaced by various RE3+ ions, where RE = Gd, Y, or Lu [5,6]. Among these, the REAlO3 perovskite compound formed by Gd3+ with a large ion radius (180.4 pm) [7] is close to the cubic crystal cell (ideal perovskite structure, Pm3m), and the symmetry is higher than that of YAlO3 (YAP) and LuAlO3 (LuAP). Thus, the high accommodation capacity of the perovskite structure helps to regulate electronic and spectroscopic properties through the substitution of Gd3+ in GAP by various activators, such as Eu3+, Er3+, Ce3+, Yb3+, and Dy3+ [8,9]. Meanwhile, the short optical cut-off length, high absorption cross section, and large atomic weight are also conductive to achieve strong and fast emissions under excitations [10].
Among the rare earth ions, Eu3+ is characterized by high luminescence intensity and milliseconds of lifetime, and considered a promising activator in red phosphors or scintillators [11,12,13,14]. In addition, in the distorted GdO12 polyhedral, the sites occupied by Eu3+ ions lack inverse symmetry and satisfy both magnetic and electric dipole transitions [15,16]. In 2018, Gorbenko et al. [2] reported the epitaxial growth of Eu3+-doped RAlO3 (R = Y, Lu, Gd, Tb) single crystalline film for scintillating screens, finding that the Gd3+ → Eu3+ energy transfer improved the luminescence efficiency of Eu3+. In addition, the high segregation coefficient of Eu3+ ions in GAP, i.e., 0.97–1.03, indicated that Eu3+ can be accommodated in a wide concentration range. Furthermore, GAP has a low thermal expansion coefficient [17] and high thermal conductivity [18,19,20], which is suitable for crystal growth.
Based on composition engineering, cation substitution was used to modify the crystal field and the energy level positions of the activators and traps in the bandgap. A considerable enhancement of red emissions was achieved by co-doping Tb3+ [9,21], Dy3+ [8,22], or Yb3+ [23] to Eu:GAP phosphors. However, composition engineering in GAP, such as Eu:(M,Gd)AlO3 (Eu:MAP, M = La, Lu, Y), was rarely reported. The composition regulation has shown a significant effect on the scintillation properties in the garnet structures Gd3Al5O12 (GAG) [24,25,26]. The modification of host components is mostly to replace Gd sites with lanthanide ions, such as LaAlO3 (LAP) with space group Pm3m (No. 221), which shows an extremely stable structure at room temperature [27]. However, it cannot be considered as a traditional host material because it lacks a 4f electron layer [28].
Eu:GAP powder phosphors have been widely studied. Broadband or line-spectral luminescence in multiple bands in the 590–696 nm range can be observed in Eu:GAP phosphor synthesized by various methods, such as the sol–gel process, co-precipitation method, combustion synthesis, and precursor decomposition approach [29,30,31]. Luo et al. [32] investigated the Eu concentration effect in GAP powder phosphors and concluded that the 8 at.% Eu-doped GAP reached the maximum luminescence intensity. Compared with powders, the single crystal has high lattice integrity because of the low defect concentration inside it [33], helping to achieve high luminescence efficiency. However, the growth of GAP crystals has rarely been reported so far.
We investigated the growth of 8 at.% Eu-doped GAP and GLAP single crystals using the optical floating zone (OFZ) method in this work. The optical quality and photoluminescence (PL) properties of the single crystals were investigated in detail. Furthermore, the radioluminescence was also characterized by X-ray excitation.

2. Materials and Methods

2.1. Crystal Growth

The starting high-purity raw materials (≥99.99%, Eu2O3, La2O3, Gd2O3, α-Al2O3) were weighed according to the chemical stoichiometric of (Eu0.08LaxGd0.92-x)AlO3, where x = 0, 50%, i.e., Eu0.08Gd0.92AlO3 and Eu0.08Gd0.5La0.42AlO3, respectively. Then, they were mixed using an automatic agate mortar and an additional 1 wt.% B2O3 was used as the flux. The mixed powders were calcined and molded to rods with a dimension of Ø 8 mm × 100 mm for cold isostatic pressing treatment under 70 MPa for 20 min. The as-prepared rods were sintered to the feed ceramics rod in the tube furnace at 1600 °C for 8 h with flowing O2.
The optical floating zone furnace (FZ-T1000H CSC Cop., Tokyo, Japan) was used for the crystal growth. The feed rod was fixed with platinum wire on the upper side, and the seed crystal was fixed with nickel wire on the lower side. Firstly, we used a GAP ceramic rod as a seed rod, and then the obtained GAP crystal was used as the seed for the successive growth. During the growth process, the feed and seed rods rotate in opposite directions to stir the molten zone sufficiently. The growth rate (i.e., the moving speed of the halogen lamp stand) was set to 5 mm/h and the rotation speed was set to 20 rpm. High-purity (100%) oxygen was used as the growth atmosphere to help to reduce the concentration of defects such as oxygen vacancy. The heat source was aligned with the lower end of the feeding rod to realize inoculation with the seed rod after melting, and then the solid–liquid interface moved continuously with the platform (heat source) to realize the gradual solidification of the melt and finally complete the equal diameter growth. Partial crystals cut into pieces were put into the tube furnace for annealing in flowing Ar (+5% H2) at 1000 °C for 4 h. Double-sided crystal blocks polished to size Ø 6 mm × 3 mm were used for the absorption spectrum measurement.

2.2. Characterization

To determine the phase purity and crystal structure, the as-grown crystals were ground into uniformly distributed powders for powder X-ray diffraction (PXRD) measurement at room temperature using the Rigaku Ultima IV diffractometer (Cu Kα, 40 kV, 40 mA, Rigaku Ultima IV, Tokyo, Japan). The scanning speed was 5°/min in the range of 20~90°. The absorbance spectra of the crystals were measured using a UV−Vis−NIR photometer (Varian Cary 5000, Cary 5000, Agilent Technologies Inc., Santa Clara, CA, USA), and the apparatus baseline was subtracted automatically. PL and excitation (PLE) spectra were recorded using a fluorescence spectrometer (Hitachi F-4600, Tokyo, Japan). The steady-state radioluminescence XEL spectra of the samples were measured using the self-assembled X-ray fluorescence spectrometer (X-ray tube: 70 kV, 1.5 mA, Ruhai Cop., Shanghai, China).

3. Results

Figure 1a shows a photograph of the as-grown Eu:GAP and Eu:GLAP crystals rods. All of the crystals are almost crack-free and are of a dark brown color. Figure 1b shows the crystal circle pieces cut vertically along the direction of crystal growth. After annealing in flowing Ar (+5% H2), the Eu:GLAP crystal pieces appeared transparent, while the Eu:GAP crystals were an opaque white.
Figure 2 shows the PXRD patterns of the as-grown Eu:GAP and Eu:GLAP crystals. All diffraction peaks of the crystals matched well with the standard GAP (PDF#46-0395), indicating a formation of the desired perovskite GAP phase. All crystals show a similar crystal structure and belong to the cubic crystal pm3m space group. In addition, the absence of secondary phases indicates that Eu3+ completely entered into the GAP lattice through a solid solution [21]. In addition, the diffraction peak did not present a dramatic shift, which might indicate that the lattice constants of Eu:GAP and Eu:GLAP crystals are similar.
Figure 3 gives the Laue photograph of the Eu:GAP and Eu:GLAP crystals, as grown and after the air annealing process. The clear and well symmetric diffraction patterns demonstrated a high single crystal quality.
In Figure 4, the absorbance spectra of the Eu:GAP and Eu:GLAP crystals with and without the Ar (+5% H2) atmosphere annealing process are presented. The strong absorption in the 200–350 nm range is ascribed to the characteristic absorption of the Eu-O charge transfer band (CTB), corresponding to the electron transition from 2p of O2− to Eu3+ 4f, indicating that Eu3+ has successfully partially replaced the octa-coordinated Gd3+ ion site. The weak absorption peaks appearing at 320 nm are related to 8S7/2 →6Pj of Gd3+. Its 6Pj energy level can be used as a platform for transmitting energy to the higher energy level 4f6 of Eu3+ ion to improve the energy transfer efficiency. In addition, the sharp and weak absorption peak at approximately 400 nm is related to the 4f-4f transition of Eu3+. It is also worth noting that the redshift of the absorption cutoff occurred in Eu:GAP crystals regarding Eu:GLAP crystals, which reveals the band gap difference between them. The absorbance of the Eu:GAP crystals in the 400–800 nm range is still around 2, which indicates a low transparency of the crystals. We suspect that the small number of inclusions and cracks might be the possible light scattering sources that introduced a decrease in the optical transmittance. The crystal growth parameters should be investigated carefully in the future to improve the optical quality, axial homogeneity, and radial homogeneity of the as-grown crystals.
The PLE (λem = 617 nm) and PL (λex = 275 nm) spectra of the Eu:GAP and Eu:GLAP crystal powders are shown in Figure 5, respectively. All samples exhibited a similar spectral line and can be considered to possess the same luminescence phenomenon. As shown in Figure 5a, the excitation peaks of the Eu:GAP and Eu:GLAP crystals matched well with each other in terms of the wavelength position, although there was a difference in the intensity. The emission in the 200–350 nm range originated from the O2−-Eu3+ charge transfer band (CTB) transition. In addition, the excitation peaks at 360 nm (7F0 → 5L0), 373–383 nm (7F0 → 5G3), 396 nm (7F0 → 5L6), 415 nm (7F0 → 5D3), and 466 nm (7F0 → 5D2) can be attributed to the 4f-4f transition of Eu3+ ions [20]. Figure 5b shows the emission spectra recorded under 275 nm excitation. The emission of the Eu:GAP single crystal in the red region is stronger than that of the La co-doped crystal and the emission spectra of all samples are the 4f characteristic sharp line emission of Eu3+, i.e., 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transition. Among them, the emission at 592 nm belongs to the 5D0–7F1 transition allowed by the magnetic dipole without an electric dipole contribution. The red emission at 617 nm and 625 nm only originates from the 5D0 → 7F2 electric dipole transition of Eu3+. Unlike magnetic dipole transitions, electric dipole transitions with higher transition strength are highly sensitive to the local environmental symmetry around Eu3+ ions [34]. The emission at 556, 655, and 706 nm results from 5D0 → 7F0, 5D0 → 7F3 and 5D0 → 7F4 transitions [35,36]. A near-infrared (NIR) emission at 836 nm was also observed.
In Figure 5b, the significantly improved PL intensity of the as grown Eu:GAP crystal regarding other crystals can be attributed to the enhanced crystallinity or possibly higher effective Eu concentration, since the crystals will exhibit axial or radial inhomogeneity in different positions of the crystal rods [37,38]. In this work, we only cut the part that had good crystal integrity and used it for the following measurement. This means that the selected crystals came from random positions. In addition, considering that the wavelength range that human eyes can perceive is located at 400–700 nm [39], the 556 and 655 nm emission of Eu:GAP and Eu:GLAP indicated a potential application in high-efficiency warm white lighting. Significantly, their broad emission at 655 nm and 706 nm matched well with the absorption band of red/phytochrome (PR) and far-red/phytochrome (PFR) of plants [40], indicating the potential plant lighting application of Eu:GAP and Eu:GLAP.
Figure 6 recorded the temperature evolution of PL spectra under an excitation of 275 nm. The investigated temperature range was from room temperature (RT) to 225 °C. The PL intensity varied with the increase in the temperature, which can be attributed to the thermal quenching effect. Figure 7 reveals the temperature dependence of PL integral intensity in a clearer way. The Eu:GLAP crystal exhibited a better thermal stability. Therefore, considering the homogeneity effect in different positions of the crystal rods, as we discussed in Figure 1 and Figure 5, a further systematic study on La substitution concentration to Gd, i.e., La and Gd ration in Eu:LGAP, needs to be conducted.
Figure 8 shows the Commission Internationale de L’Eclairage (CIE) chromaticity diagram of the Eu:GAP and Eu:GLAP crystals. The color coordinates are shown in Table 1. The color coordinates of the Eu:GAP crystal are (0.4903, 0.507), located in the orange-yellow region. After annealing, the color coordinates of the Eu3+ ions move towards the orange-red region for crystals with Eu3+ single-doping and Eu3+/La3+ co-doping, which gives it important application potential in warm white lighting. In addition, the application potential of the Eu:GAP and Eu:GLAP crystals in radiation detection are also explored.
The XEL spectra of the Eu:GAP and Eu:GLAP crystals with or without the 1000 °C for 4 h in Ar + 5% H2 annealing process are shown in Figure 9, with a Bi4Ge3O12 (BGO) single crystal as a reference sample. The typical 5D0 → 7FJ transition of Eu3+ under X-ray excitation was almost the same as that of the PL (λex = 275 nm) spectra. The significantly increased strength of the annealed crystals is expected to make them a potential candidate for applications in X-ray detection and imaging.

4. Conclusions

Eu:GAP and Eu:GLAP single crystals were successfully grown using the OFZ method, which had rarely been reported before. The XRD patterns show that the as-grown crystals are the GAP phase with the integral cubic perovskite structure. All crystals show a strong absorption in the 200–300 nm range, originating from the characteristic absorption of the Eu-O charge transfer band (CTB). The obvious absorption cutoff occurs at 300 nm in GLAP. In contrast, the Eu:GAP single crystal has a stronger emission in the red region and an obvious strong emission band under the 275 nm excitation located at 556 nm, 592 nm, 617 nm, 625 nm, 655 nm, and 706 nm corresponding to the 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3, and 5D0 → 7F4 transitions of Eu3+. The CIE chromaticity coordinates shows the emitted color shifts from the orange-yellow region to the orange-red region for the annealed crystal. Except for the application value in the field of solid-state lighting, the intense luminescence phenomenon under X-ray excitation demonstrated its potential application in the radiation detection field.

Author Contributions

Conceptualization, Y.S.; methodology, T.W., Q.Z., Y.S., L.W., Y.X. and H.W.; software & validation, T.W., L.W., H.H., J.F. and J.N.; formal analysis, T.W., Q.Z., Y.X., L.W., H.W., Z.Z. and Y.S.; resources, Y.S., Z.Z., Q.L. and J.Y.; writing—original draft preparation, T.W.; writing—review and editing, Y.S., L.W., H.W., Z.Z. and Q.L.; visualization, H.H., J.F. and J.N. project administration & funding acquisition, Y.S. and J.Y. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Natural Science Foundation of China, grant number 62175249; the Strategic Priority Research Program of the Chinese Academy of Sciences, grant number xda22010301; the Research Program of Shanghai Sciences and Technology Commission Foundation, grant number 22511100300.

Acknowledgments

Kun Chen and Yinghui Shi from the Artificial Crystal Research Center of Shanghai Institute of Ceramics, Chinese Academy of Sciences, are thanked for their help with the absorbance measurements. Shuwen Zhao and Dongzhou Ding from the Artificial Crystal Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, are thanked for their helpful contribution to the measurement of the scintillation light yield.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Celik, E.; Yamada, Y.; Hirabayashi, I.; Shiohara, Y. Nb-doped SrTiO3 buffer layers on LaAlO3 substrates by metalorganic deposition for YBCO superconducting films. Mater. Sci. Eng. B-Adv. 2004, 110, 94–102. [Google Scholar] [CrossRef]
  2. Gorbenko, V.; Zorenko, T.; Paprocki, K.; Riva, F.; Douissard, P.A.; Martin, T.; Zhydachevskii, Y.; Suchocki, A.; Fedorov, A.; Zorenko, Y. Epitaxial growth of single crystalline film scintillating screens based on Eu3+ doped RAlO3 (R = Y, Lu, Gd, Tb) perovskites. Crystengcomm 2018, 20, 937–945. [Google Scholar] [CrossRef]
  3. Jisha, P.K.; Naik, R.; Prashantha, S.C.; Nagabhushana, H.; Sharma, S.C.; Nagaswarupa, H.P.; Anantharaju, K.S.; Prasad, B.D.; Prernkumar, H.B. Facile combustion synthesized orthorhombic GdAlO3:Eu3+ nanophosphors: Structural and photoluminescence properties for WLEDs. J. Lumin. 2015, 163, 47–54. [Google Scholar] [CrossRef]
  4. du Boulay, D.; Ishizawa, N.; Maslen, E.T. GdAlO3 perovskite. Acta Crystallogr. C 2004, 60 Pt 12, i120–i122. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  5. Vilejshikova, E.V.; Khort, A.A.; Podbolotov, K.B.; Loiko, P.A.; Shimanski, V.I.; Shashkov, S.N.; Yumashev, K.V. Luminescence of Eu:Y3Al5O12, Eu:Lu3Al5O12, and Eu:GdAlO3 Nanocrystals Synthesized by Solution Combustion. J. Appl. Spectrosc. 2017, 84, 866–874. [Google Scholar] [CrossRef]
  6. Han, S.D.; Khatkar, S.P.; Taxak, V.B.; Kumar, D.; Park, J.Y. Combustion synthesis and luminescent properties of Eu3+−doped LnAlO3 (Ln = Y and Gd) phosphors. Mater. Sci. Eng. B-Adv. 2006, 127, 272–275. [Google Scholar] [CrossRef]
  7. Speight, J.G. LANGE’S Handbook of Chemistry Sixteenth Edition; CD&W Inc.: Laramie, WY, USA, 2008. [Google Scholar]
  8. Tamrakar, R.K.; Tiwari, S.; Upadhyay, K.; Robinson, C.S. Synthesis, structural and luminescent properties of Eu2+/Dy3+ activated GdAlO3 phosphors by solid state reaction method under nitrogen atmosphere. Optik 2019, 181, 1158–1162. [Google Scholar] [CrossRef]
  9. Chen, Q.; Li, J.; Wang, W. Synthesis and luminescence properties of Tb3+/Eu3+ co-doped GdAlO3 phosphors with enhanced red emission. J. Rare Earths 2018, 36, 924–930. [Google Scholar] [CrossRef]
  10. Verweij, J.; Cohen-Adad, M.T.; Bouttet, D.; Lautesse, H.; Moine, B.; Pédrini, C. Luminescence properties of GdAlO3: Ce powders. Dependence on reduction conditions. Chem. Phys. Lett. 1995, 239, 51–55. [Google Scholar] [CrossRef]
  11. Venkatesh, R.; Dhananjaya, N.; Sateesh, M.K.; Begum, J.P.S.; Yashodha, S.R.; Nagabhushana, H.; Shivakumara, C. Effect of Li, Na, K cations on photoluminescence of GdAlO3:Eu3+ nanophosphor and study of Li cation on its antimicrobial activity. J. Alloys Compd. 2018, 732, 725–739. [Google Scholar] [CrossRef]
  12. Dong, H.; Sun, L.D.; Yan, C.H. Energy transfer in lanthanide upconversion studies for extended optical applications. Chem. Soc. Rev. 2015, 44, 1608–1634. [Google Scholar] [CrossRef] [PubMed]
  13. Xu, W.L.; Jia, W.Y.; Revira, I.; Monge, K.; Liu, H.M. Optical properties of multiple sites of Eu3+ in SrY2O4 single-crystal fibers. J. Electrochem. Soc. 2001, 148, H176–H178. [Google Scholar] [CrossRef]
  14. Moine, B.; Bizarri, G. Rare-earth doped phosphors: Oldies or goldies? Mater. Sci. Eng. B-Adv. 2003, 105, 2–7. [Google Scholar] [CrossRef]
  15. Makhov, V.N.; Lushchik, C.; Lushchik, A.; Kirm, M.; Wang, Z.F.; Zhang, W.P.; Yin, M.; Zhao, J.T. Multiplication of electronic excitations in nanophosphors Lu2O3:Eu3+ and Lu2O3:Tb3+. J. Lumin. 2009, 129, 1711–1714. [Google Scholar] [CrossRef] [Green Version]
  16. Ross, N.L.; Zhao, J.; Angel, R.J. High-pressure single-crystal X-ray diffraction study of YAlO3 perovskite. J. Solid State Chem. 2004, 177, 1276–1284. [Google Scholar] [CrossRef]
  17. Chaudhury, S.; Parida, S.C.; Pillai, K.T.; Singh Mudher, K.D. High-temperature X-ray diffraction and specific heat studies on GdAlO3, Gd3Al5O12 and Gd4Al2O9. J. Solid State Chem. 2007, 180, 2393–2399. [Google Scholar] [CrossRef]
  18. Suresh, G.; Seenivasan, G.; Krishnaiah, M.; Murti, P.S. Investigation of the thermal conductivity of selected compounds of gadolinium and lanthanum. J. Nucl. Mater. 1997, 249, 259–261. [Google Scholar] [CrossRef]
  19. Upadhyay, K.; Tamrakar, R.K.; Dubey, V. High temperature solid state synthesis and photoluminescence behavior of Eu3+ doped GdAlO3 nanophosphor. Superlattices Microstruct. 2015, 78, 116–124. [Google Scholar] [CrossRef]
  20. Shilpa, C.J.; Jayaram, A.K.; Dhananjaya, N.; Nagabhushana, H.; Prashantha, S.C.; Sunitha, D.V.; Sharma, S.C.; Shivakumara, C.; Nagabhushana, B.M. GdAlO3:Eu3+:Bi3+ nanophosphor: Synthesis and enhancement of red emission for WLEDs. Spectrochim. Acta A 2014, 133, 550–558. [Google Scholar] [CrossRef]
  21. Oliveira, H.; Cebim, M.A.; Silva, A.; Davolos, M.R. Structural and optical properties of GdAlO3:RE3+ (RE = Eu or Tb) prepared by the Pechini method for application as X-ray phosphors. J. Alloys Compd. 2009, 488, 619–623. [Google Scholar] [CrossRef]
  22. Selvalakshmi, T.; Venkatesan, P.; Wu, S.P.; Velmathi, S.; Bose, A.C. Gd2O3:RE3+ and GdAlO3:RE3+ (RE = Eu, Dy) Phosphor: Synthesis, Characterization and Bioimaging Application. J. Nanosci. Nanotechnol. 2017, 17, 1178–1184. [Google Scholar] [CrossRef]
  23. Tamrakar, R.K.; Upadhyay, K.; Sahu, M. Spectral characterization of Er3+, Yb3+ co doped GdAlO3 phosphor prepared by solid state reaction method. J. Alloys Compd. 2016, 689, 702–712. [Google Scholar] [CrossRef]
  24. Kamada, K.; Yanagida, T.; Pejchal, J.; Nikl, M.; Endo, T.; Tsutumi, K.; Fujimoto, Y.; Fukabori, A.; Yoshikawa, A. Scintillator-oriented combinatorial search in Ce-doped (Y,Gd)3(Ga,Al)5O12 multicomponent garnet compounds. J. Phys. D Appl. Phys. 2011, 44, 505104. [Google Scholar] [CrossRef]
  25. Kamada, K.; Endo, T.; Tsutumi, K.; Yanagida, T.; Fujimoto, Y.; Fukabori, A.; Yoshikawa, A.; Pejchal, J.; Nikl, M. Composition Engineering in Cerium-Doped (Lu,Gd)3(Ga,Al)5O12 Single-Crystal Scintillators. Cryst. Growth Des. 2011, 11, 4484–4490. [Google Scholar] [CrossRef]
  26. Wu, T.; Wang, L.; Shi, Y.; Huang, X.T.; Zhang, Q.; Xiong, Y.; Wang, H.; Fang, J.H.; Ni, J.Q.; He, H.; et al. Wide Concentration Range of Tb3+ Doping Influence on Scintillation Properties of (Ce, Tb, Gd)3Ga2Al3O12 Crystals Grown by the Optical Floating Zone Method. Materials 2022, 15, 2044. [Google Scholar] [CrossRef]
  27. Liu, X.M.; Yan, L.S.; Lin, J. Synthesis and Luminescent Properties of LaAlO3:RE3+ (RE = Tm, Tb) Nanocrystalline Phosphors via a Sol-Gel Process. J. Phys. Chem. C 2009, 113, 8478–8483. [Google Scholar] [CrossRef]
  28. Liu, G.Y.; Wang, B.; Li, J.K.; Cao, B.Q.; Lu, Y.Z.; Liu, Z.M. Research progress of gadolinium aluminum garnet based optical materials. Physica B 2021, 603, 412775. [Google Scholar] [CrossRef]
  29. Sinha, A.; Nair, S.R.; Sinha, P.K. Single step synthesis of GdAlO3 powder. J. Alloys Compd. 2011, 509, 4774–4780. [Google Scholar] [CrossRef]
  30. Kuo, C.L.; Wang, C.L.; Chen, T.Y.; Chen, G.J.; Hung, I.M.; Shih, C.J.; Fung, K.Z. Low temperature synthesis of nanocrystalline lanthanum monoaluminate powders by chemical coprecipitation. J. Alloys Compd. 2007, 440, 367–374. [Google Scholar] [CrossRef]
  31. Chen, B.H.; Yu, J.F.; Liang, X. LaAlO3 Hollow Spheres: Synthesis and Luminescence Properties. Langmuir 2011, 27, 11654–11659. [Google Scholar] [CrossRef] [PubMed]
  32. Luo, L.; Liu, Q.; Liu, Q. Luminescent Properties and Mechanism of Co-Doped GdAlO3: RE. Photogr. Sci. Photochem. 2005, 23, 1–5. [Google Scholar]
  33. Wu, T.; Wang, L.; Xu, T.; Wang, H.; Wang, C.; Huang, X.; Shen, H.; Shi, Y. Research progress of (Ce, Gd)3(Ga, Al)5O12 (Ce:GGAG) scintillator for medical CT. Chin. J. Technol. 2021, 21, 109–125. [Google Scholar]
  34. Venkatesh, R.; Dhananjaya, N.; Shivakumara, C. Effects of monovalent cation doping on the structure and photoluminescence of GdAlO3: Eu3+ phosphor. Int. J. Nanotechnol. 2017, 14, 793–800. [Google Scholar] [CrossRef]
  35. Shivram, M.; Prashantha, S.C.; Nagabhushana, H.; Sharma, S.C.; Thyagarajan, K.; Harikrishna, R.; Nagabhushana, B.M. CaTiO3:Eu3+ red nanophosphor: Low temperature synthesis and photoluminescence properties. Spectrochim. Acta A 2014, 120, 395–400. [Google Scholar] [CrossRef] [PubMed]
  36. Hirata, G.; Perea, N.; Tejeda, M.; Gonzalez-Ortega, J.A.; McKittrick, J. Luminescence study in Eu-doped aluminum oxide phosphors. Opt. Mater. 2005, 27, 1311–1315. [Google Scholar] [CrossRef]
  37. Yoshikawa, A.; Fujimoto, Y.; Yamaji, A.; Kurosawa, S.; Pejchal, J.; Sugiyama, M.; Wakahara, S.; Futami, Y.; Yokota, Y.; Kamada, K.; et al. Crystal growth and characterization of Ce:Gd3(Ga,Al)5O12 single crystal using floating zone method in different O2 partial pressure. Opt. Mater. 2013, 35, 1882–1886. [Google Scholar] [CrossRef]
  38. Xiong, Y.; Shi, Y.; Wang, H.; Zhang, Q.; Wu, T.; Yuan, Q.; Ma, K.; Li, T.; Zhou, Z.; Fang, J.; et al. Ce3+, Pr3+ Co-Doped Lu3Al5O12 Single Crystals and Ceramics: A Comparative Study. Materials 2022, 15, 9025. [Google Scholar] [CrossRef]
  39. Tianyuan, Z.; Chen, H.O.U.; Le, Z.; Yuelong, M.A.; Jian, K.; Tao, L.I.; Rui, W.; Jin, H.; Junwei, L.I.; Haidong, R.E.N.; et al. Efficient spectral regulation in Ce:Lu3(Al,Cr)5O12 and Ce:Lu3(Al,Cr)5O12/Ce:Y3Al5O12 transparent ceramics with high color rendering index for high-power white LEDs/LDs. J. Adv. Ceram. 2021, 10, 1107–1118. [Google Scholar]
  40. Zou, X.; Wang, X.; Zhang, H.; Kang, Y.; Yang, X.; Zhang, X.; Molokeev, M.S.; Lei, B. A highly efficient and suitable spectral profile Cr3+-doped garnet near-infrared emitting phosphor for regulating photomorphogenesis of plants. Chem. Eng. J. 2022, 428, 132003. [Google Scholar] [CrossRef]
Materials 16 00488 g001 550
Figure 1. Photographs of the (a) as-grown Eu:GAP and Eu:GLAP crystal rods; (b) double face polished Eu:GAP and Eu:GLAP single crystals, from left to right, as-grown Eu:GAP and annealed Eu:GAP crystals, as-grown Eu:GLAP and annealed Eu:GLAP crystals, 1 mm thickness.
Figure 1. Photographs of the (a) as-grown Eu:GAP and Eu:GLAP crystal rods; (b) double face polished Eu:GAP and Eu:GLAP single crystals, from left to right, as-grown Eu:GAP and annealed Eu:GAP crystals, as-grown Eu:GLAP and annealed Eu:GLAP crystals, 1 mm thickness.
Materials 16 00488 g001
Materials 16 00488 g002 550
Figure 2. PXRD patterns of the as-grown Eu:GAP and Eu:GLAP single crystals.
Figure 2. PXRD patterns of the as-grown Eu:GAP and Eu:GLAP single crystals.
Materials 16 00488 g002
Materials 16 00488 g003 550
Figure 3. Laure graph of (a) as-grown Eu:GAP crystal; (b) annealed Eu:GAP crystal; (c) Eu:GLAP single crystals; (d) annealed Eu:GLAP crystal.
Figure 3. Laure graph of (a) as-grown Eu:GAP crystal; (b) annealed Eu:GAP crystal; (c) Eu:GLAP single crystals; (d) annealed Eu:GLAP crystal.
Materials 16 00488 g003
Materials 16 00488 g004 550
Figure 4. Absorbance spectra of the as-grown and annealed Eu:GAP and Eu:GLAP crystals (after double-side polishing to 1.0 mm thickness).
Figure 4. Absorbance spectra of the as-grown and annealed Eu:GAP and Eu:GLAP crystals (after double-side polishing to 1.0 mm thickness).
Materials 16 00488 g004
Materials 16 00488 g005 550
Figure 5. Photoluminescence spectra of the as-grown Eu:GAP and Eu:GLAP crystals; (a) PLE λem = 617 nm; (b) PL λex = 275 nm.
Figure 5. Photoluminescence spectra of the as-grown Eu:GAP and Eu:GLAP crystals; (a) PLE λem = 617 nm; (b) PL λex = 275 nm.
Materials 16 00488 g005
Materials 16 00488 g006 550
Figure 6. PL spectra of the (a) Eu:GAP crystal; (b) Eu:GLAP crystal with the post Ar (+5% H2) annealing process; (c) as-grown Eu:GAP crystal and (d) as-grown Eu:GLAP crystal at different temperatures from RT to 225 °C.
Figure 6. PL spectra of the (a) Eu:GAP crystal; (b) Eu:GLAP crystal with the post Ar (+5% H2) annealing process; (c) as-grown Eu:GAP crystal and (d) as-grown Eu:GLAP crystal at different temperatures from RT to 225 °C.
Materials 16 00488 g006
Materials 16 00488 g007 550
Figure 7. Temperature dependence of PL integral intensity of Eu:GAP and Eu:GLAP crystals with or without post Ar (+5% H2) annealing process, λex = 275 nm.
Figure 7. Temperature dependence of PL integral intensity of Eu:GAP and Eu:GLAP crystals with or without post Ar (+5% H2) annealing process, λex = 275 nm.
Materials 16 00488 g007
Materials 16 00488 g008 550
Figure 8. CIE chromaticity coordinates for the (a) as-grown Eu:GAP crystal; (b) annealed Eu:GAP crystal; (c) as-grown Eu:GLAP crystal; (d) annealed Eu:GLAP crystal.
Figure 8. CIE chromaticity coordinates for the (a) as-grown Eu:GAP crystal; (b) annealed Eu:GAP crystal; (c) as-grown Eu:GLAP crystal; (d) annealed Eu:GLAP crystal.
Materials 16 00488 g008
Materials 16 00488 g009 550
Figure 9. XEL spectra of (a) Eu:GAP and (b) Eu:GLAP crystals, with or without the 1000 °C for 4 h in Ar + 5% H2 annealing process. Five times the XEL intensity of a BGO single crystal was used for quantitative comparison.
Figure 9. XEL spectra of (a) Eu:GAP and (b) Eu:GLAP crystals, with or without the 1000 °C for 4 h in Ar + 5% H2 annealing process. Five times the XEL intensity of a BGO single crystal was used for quantitative comparison.
Materials 16 00488 g009
Table
Table 1. Summarized color coordinates of Eu:GAP and Eu:GLAP crystals with or without the 1000 °C for 4 h in Ar + 5% H2 annealing process.
Table 1. Summarized color coordinates of Eu:GAP and Eu:GLAP crystals with or without the 1000 °C for 4 h in Ar + 5% H2 annealing process.
No.SamplesCIE xCIE y
aEu:GAP (as grown)0.49030.5070
bEu:GAP (annealed)0.64500.3543
cEu:GLAP (as grown)0.51870.4787
dEu:GLAP (annealed)0.63380.3652
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wu, T.; Zhang, Q.; Shi, Y.; Wang, L.; Xiong, Y.; Wang, H.; Fang, J.; Ni, J.; He, H.; Zhou, Z.; et al. Eu3+-Doped (Gd, La)AlO3 Perovskite Single Crystals: Growth and Red-Emitting Luminescence. Materials 2023, 16, 488. https://doi.org/10.3390/ma16020488

AMA Style

Wu T, Zhang Q, Shi Y, Wang L, Xiong Y, Wang H, Fang J, Ni J, He H, Zhou Z, et al. Eu3+-Doped (Gd, La)AlO3 Perovskite Single Crystals: Growth and Red-Emitting Luminescence. Materials. 2023; 16(2):488. https://doi.org/10.3390/ma16020488

Chicago/Turabian Style

Wu, Tong, Qian Zhang, Yun Shi, Ling Wang, Yifei Xiong, Hui Wang, Jinghong Fang, Jinqi Ni, Huan He, Zhenzhen Zhou, and et al. 2023. "Eu3+-Doped (Gd, La)AlO3 Perovskite Single Crystals: Growth and Red-Emitting Luminescence" Materials 16, no. 2: 488. https://doi.org/10.3390/ma16020488

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop