1
|
Singh P, Modanwal S, Mishra H, Rai SB. Intense photoluminescence in CaTiO 3:Sm 3+ phosphors, effect of co-doping singly, doubly and triply ionized elements and their applications in LEDs. RSC Adv 2023; 13:22663-22674. [PMID: 37502827 PMCID: PMC10369130 DOI: 10.1039/d3ra04468h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 07/09/2023] [Indexed: 07/29/2023] Open
Abstract
In this work, Sm3+-doped and Sm3+/Li+/K+/Mg2+/Ba2+/Gd3+/Bi3+ co-doped CaTiO3 phosphors were synthesized by a solid-state reaction method at 1473 K. The phase of phosphors was identified to be orthorhombic with space group Pnma (62) by XRD measurements. The morphological properties of the prepared samples were studied by SEM measurements. The average crystallite and particle sizes were found to increase in the presence of modifiers and they follow the trend Li+ > Mg2+ > Gd3+ > K+ > Bi3+ > Ba2+. EDX measurements were used to verify the presence of Ca, Ti, O, Sm, K, Mg, Ba, Gd and Bi atoms in the prepared phosphor samples. The Sm3+ ion shows emission peaks at 564, 599 and 646 nm due to 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 transitions upon 407 nm excitation, among which the peak situated at 599 nm has maximum emission intensity. Concentration quenching was observed above 2 mol% of Sm3+ ions in this host. However, the emission intensity of Sm3+ peaks can be enhanced using different modifier (Li+/K+/Mg2+/Ba2+/Gd3+/Bi3+) ions. It was found that the size (ionic radii) and charge compensation of the ion together play a dominant role. The enhancement is more after co-doping with smaller radius ions (Li+, Mg2+ and Gd3+), among which Li+ shows the largest enhancement. This is because ions of smaller size will be able to go closer to the activator ion and the charge imbalance causes a larger field. The CIE color coordinates, correlated color temperature (CCT) and color purity of the phosphors were calculated and show orange-red color emissions with a maximum color purity of ∼93% in the case of CaTiO3:2Sm3+/1.0Li+ phosphor. The lifetime value is increased in the presence of these ions. It is again maximum for the Li+ co-doped CaTiO3:2Sm3+ phosphor sample. Thus, the prepared phosphor samples are suitable sources for orange-red light.
Collapse
Affiliation(s)
- Priti Singh
- Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University Varanasi 221005 India
| | - Sumit Modanwal
- Physics Section, Mahila Maha Vidyalaya, Department of Physics, Banaras Hindu University Varanasi 221005 India
| | - Hirdyesh Mishra
- Physics Section, Mahila Maha Vidyalaya, Department of Physics, Banaras Hindu University Varanasi 221005 India
| | - Shyam Bahadur Rai
- Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University Varanasi 221005 India
| |
Collapse
|
2
|
Singh P, Mishra H, Pandey PC, Rai SB. Structure, photoluminescence properties, and energy transfer phenomenon in Sm 3+/Eu 3+ co-doped CaTiO 3 phosphors. NEW J CHEM 2023. [DOI: 10.1039/d2nj05774c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The energy transfer from Sm3+ and Eu3+ due to dipole–dipole interaction, variation in emission intensity of Sm3+ and Eu3+ peaks with varying concentration of Eu3+ and thermal stability of 2Sm3+, 2.5Eu3+ and 2Sm3+/2.5Eu3+ co-doped CaTiO3 phosphors.
Collapse
Affiliation(s)
- Priti Singh
- Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - H. Mishra
- Mahila Maha Vidyalaya, Banaras Hindu University, Varanasi 221005, India
| | - Praveen C. Pandey
- Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
| | - Shyam Bahadur Rai
- Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| |
Collapse
|
3
|
Wu W, Zhang Y, Zhang Y, Hu J. Ba 3YB 3O 9 based phosphor ceramic plates with excellent thermal stability for wLED applications. Dalton Trans 2021; 50:5287-5300. [PMID: 33881095 DOI: 10.1039/d1dt00194a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A series of Eu3+ and Tb3+ singly doped Ba3YB3O9 phosphors were synthesized by a solution combustion approach. The most luminescent phosphors were selected as the starting materials to fabricate phosphor ceramic plates (PCPs). More intense red and green emission is observed from the PCPs than the corresponding phosphors. The emission colour can be effectively tuned by varying the mass ratio of the red and green phosphors and the excitation wavelength. White light emission was obtained by incorporating the blue-emitting Eu2+ doped BaMgAl10O17 phosphor into the PCP component. The synthesized phosphors and PCPs show robust thermal stability, maintaining more than 80% of emission intensity at 423 K of that at 298 K after a long time operation. The results indicate that the prepared red and green PCPs are promising candidates for high-power wLED applications.
Collapse
Affiliation(s)
- Weiwei Wu
- Key laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang 315211, China.
| | - Yuanpeng Zhang
- Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USA
| | - Yuepin Zhang
- Key laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang 315211, China.
| | - Jianxu Hu
- Key laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang 315211, China.
| |
Collapse
|
4
|
Gupta SK, Prasad KS, Pathak N, Kadam R. Color tuning in CaZrO3:RE3+ perovskite by choice of rare earth ion. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128776] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Azeem PA, Evangeline B, Haranath D, Rao RP. Investigation of lanthanum-sensitized CaZrO 3 blue nanophosphors for white light-emitting diode applications. LUMINESCENCE 2020; 36:481-488. [PMID: 33080101 DOI: 10.1002/bio.3967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/04/2020] [Accepted: 10/11/2020] [Indexed: 11/07/2022]
Abstract
In the present study, CaZrO3 nanophosphors were sensitized with lanthanum (La) at different concentrations (0.5, 1.0, 1.5, 2.0, and 2.5) prepared using polyvinyl alcohol as the chelating agent through the sol-gel method. To study their structural and optical properties, samples were characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence (PL). The XRD results revealed that samples were well crystallized and average crystallite sizes were calculated. The average crystallite size value was in good agreement with the value obtained from TEM analysis. Energy dispersive spectroscopy and FE-SEM confirmed the existence of La in the prepared samples. In the PL spectra, La-sensitized samples exhibited three bands at 402 nm, 438 nm, and 463 nm in the visible range when excited at the 260 nm wavelength. As the proportion of La increased, the intensity of bands at 438 nm and 463 nm decreased, whereas the band at 402 nm remained stable. Time-resolved PL spectra illustrated the lifetime of the samples. Corresponding CIE co-ordinates for La-sensitized CaZrO3 were calculated.
Collapse
Affiliation(s)
- P Abdul Azeem
- Department of Physics, National Institute of Technology, Warangal, India
| | - B Evangeline
- Department of Physics, National Institute of Technology, Warangal, India
| | - D Haranath
- Department of Physics, National Institute of Technology, Warangal, India
| | - R Prasada Rao
- Centre for Materials for Electronics Technology (C-MET), Pune, India
| |
Collapse
|
6
|
Gupta SK, Kadam R, Pujari P. Lanthanide spectroscopy in probing structure-property correlation in multi-site photoluminescent phosphors. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213405] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
7
|
Tamayo R, Espinoza-González R, Gracia F, Rodrigues-Filho UP, Flores M, Sacari E. As(III) Removal from Aqueous Solution by Calcium Titanate Nanoparticles Prepared by the Sol Gel Method. NANOMATERIALS 2019; 9:nano9050733. [PMID: 31086000 PMCID: PMC6566603 DOI: 10.3390/nano9050733] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/04/2022]
Abstract
Arsenic (As) contamination of water is a serious problem in developing countries. In water streams, arsenic can be as As(V) and As(III), the latter being the most toxic species. In this work, an innovative adsorbent based on CaTiO3 nanoparticles (CTO) was prepared by the sol-gel technique for the removal of As(III) from aqueous solution. X-ray diffraction of the CTO nanoparticles powders confirmed the CTO phase. Transmission electron microscopy observations indicated an average particle size of 27 nm, while energy dispersive X-ray spectroscopy analysis showed the presence of Ca, Ti, and O in the expected stoichiometric amounts. The surface specific area measured by Brunauer, Emmett, and Teller (BET) isotherm was 43.9 m2/g, whereas the isoelectric point determined by Zeta Potential measurements was at pH 3.5. Batch adsorption experiments were used to study the effect of pH on the equilibrium adsorption of As(III), using an arsenite solution with 15 mg/L as initial concentration. The highest removal was achieved at pH 3, reaching an efficiency of up to 73%, determined by X-ray fluorescence from the residual As(III) in the solution. Time dependent adsorption experiments at different pHs exhibited a pseudo-second order kinetics with an equilibrium adsorption capacity of 11.12 mg/g at pH 3. Moreover, CTO nanoparticles were regenerated and evaluated for four cycles, decreasing their arsenic removal efficiency by 10% without affecting their chemical structure. X-ray photoelectron spectroscopy analysis of the CTO surface after removal experiments, showed that arsenic was present as As(III) and partially oxidized to As(V).
Collapse
Affiliation(s)
- Rocío Tamayo
- LabMAM, Depto. de Ingeniería Química Biotecnología y Materiales, FCFM, Universidad de Chile, Av. Beauchef 851, Santiago 8370456, Chile.
| | - Rodrigo Espinoza-González
- LabMAM, Depto. de Ingeniería Química Biotecnología y Materiales, FCFM, Universidad de Chile, Av. Beauchef 851, Santiago 8370456, Chile.
| | - Francisco Gracia
- LabMAM, Depto. de Ingeniería Química Biotecnología y Materiales, FCFM, Universidad de Chile, Av. Beauchef 851, Santiago 8370456, Chile.
| | - Ubirajara Pereira Rodrigues-Filho
- Grupo de Química de Materiais Híbridos e Hinorgânicos, Instituto de Química de Sao Carlos, Universidade de São Paulo, 13563-120 Sa͂o Carlos, SP, Brazil.
| | - Marcos Flores
- Laboratorio de Superficies, Depto. de Física, FCFM, Universidad de Chile, Av. Blanco Encalada 2008, Santiago 8370449, Chile.
| | - Elisban Sacari
- Laboratorio de Nanomateriales, Facultad de Ingeniería, Universidad Nacional Jorge Basadre Grohmann, Av. Miraflores s/n, Tacna 23003, Peru.
| |
Collapse
|
8
|
Ballem E, Azeem A, Rayavarapu PR, Divi H. Structural and luminescent studies of erbium-doped CaZrO 3 green-emitting nanophosphors. LUMINESCENCE 2017; 32:1246-1251. [PMID: 28612410 DOI: 10.1002/bio.3318] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/02/2017] [Accepted: 02/21/2017] [Indexed: 11/08/2022]
Abstract
Erbium (Er) (0.5, 1.0 and 1.5 wt%)-doped CaZrO3 nanophosphors were synthesized by the sol-gel method using poly(vinyl alcohol) as the chelating agent. Their structural and photoluminescence properties were studied using X-ray diffraction (XRD), field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS), transmission electron microscopy (TEM), photoluminescence and Fourier transform infrared spectroscopy (FTIR). The XRD patterns of the samples confirm that nanoscale crystallite sizes. Agglomeration of the samples was observed using field emission scanning electron microscopy images. Energy dispersive spectroscopy measurements confirmed the existence of Ca, Zr, O and Er in the samples. Average particle sizes for the samples were calculated from transmission electron microscopy images. FTIR spectra clearly show characteristic absorption bands related to the metal oxides, as well as some other organic molecules. The photoluminescence spectra show bands in the green region. The Commission International de l'Eclairage coordinates were calculated and found to be in green region.
Collapse
Affiliation(s)
- Evangeline Ballem
- Department of Physics, National Institute of Technology, Warangal, India
| | - Abdul Azeem
- Department of Physics, National Institute of Technology, Warangal, India
| | - Prasada Rao Rayavarapu
- Department of Materials Science and Engineering, National University of Singapore, Singapore
| | - Haranath Divi
- CSIR - National Physical Laboratory, New Delhi, India
| |
Collapse
|
9
|
Orihashi T, Nakamura T, Adachi S. Resonant energy transfer in (Eu3+, Bi3+)-codoped CaZrO3red-emitting phosphor. RSC Adv 2016. [DOI: 10.1039/c6ra13429g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
10
|
Effect of Y3+, Gd 3+ and La3+ dopant ions on structural, optical and electrical properties of o-mullite nanoparticles. J RARE EARTH 2014. [DOI: 10.1016/s1002-0721(14)60031-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|