Novel multi-wavelength excitable single-component phosphor system for application in white-LEDs

Lohia, Naina; Jaiswal, Vishnu V.; Bishnoi, Swati; Swati, G.; Sharma, Shweta; Mohapatra, M.; Haranath, D.

doi:10.1016/j.ceramint.2019.09.212

Cited by 14 publications

(5 citation statements)

References 34 publications

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“…It is found that double exponential fit the curves better. The double exponential expression is given by [11]: where I 0 and I(t) are the PL emission intensities at time zero and t seconds, respectively. τ 1 , τ 2 are the lifetimes and A 1 and A 2 are fitting constants and these values are given in table 4.…”

Section: Ple and Pl Spectra Of Zno-cazo:xeu 3+ And Zno:15eu 3+ Phosph...mentioning

confidence: 99%

“…τ 1 , τ 2 are the lifetimes and A 1 and A 2 are fitting constants and these values are given in table 4. The average lifetime values could be calculated using the expression [11]:…”

Section: Ple and Pl Spectra Of Zno-cazo:xeu 3+ And Zno:15eu 3+ Phosph...mentioning

confidence: 99%

“…The coated phosphor converts the high energy radiation (UV or blue radiation from LED chip) to low energy (cool or warm white light). Certain host materials itself give white light emission on excitation with n-UV-LED's [8][9][10][11]. Such type of hosts are becoming more popular for WLED's.…”

Section: Introductionmentioning

confidence: 99%

“…The photoluminescence emission intensity of ZnO-CAZO is 4.07 times intense than the broad band emitted by pure ZnO. Lohia et al reported the multi wavelength excitable Eu 3+ doped BaZnO 2 phosphor emitting orange, red and white light as a single component system useful for white LED's [11]. So, multi wavelength excitable color tunable phosphors which also emit white light have attracted attention of researchers these days.…”

Section: Introductionmentioning

confidence: 99%

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Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study

Singh¹,

Mishra²,

Bahadur³

2023

Phys. Scr.

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Mixed phase ZnO-CAZO:xEu3+ phosphors have been synthesized by solid state reaction method to get tunable light including white light under excitation with different wavelengths. The XRD, SEM, FTIR, UV–vis absorption, photoluminescence excitation and emission spectra of the samples and the lifetime of 5D0 level of Eu3+ ions have been studied. The ZnO phosphor has well known hexagonal structure, whereas Ca3Al4ZnO10 (CAZO) has orthorhombic structure. The UV–vis spectral studies show that the materials have wide band gap. The excitation spectra of ZnO-CAZO:xEu3+ phosphors with λ em = 613 nm show broad bands at 270 and 370 nm alongwith discrete peaks due to Eu3+ ion. An excitation with 370 nm of ZnO-CAZO:xEu3+ phosphors results a broad continuum from 400–700 nm with maxima at 520 nm. The excitation with 270/394 nm on the other hand gives intense discrete peaks due to Eu3+ ion alongwith broad host emission. However, on excitation with 467 nm, it gives intense red emission with CIE coordinates (0.64, 0.36) and color purity 90%. The emission intensity is maximum for ZnO-CAZO:1.5Eu3+ phosphor. The excitation with 394 nm, results white light for ZnO-CAZO:0.5Eu3+ phosphor with CIE coordinates (0.34, 0.35), which is almost equal to the ideal white light coordinates (0.33, 0.33). The emission intensity in the mixed condition (ZnO-CAZO:1.5Eu3+) is 4.94 times greater than its single (ZnO:1.5Eu3+) phase under 370 nm excitation.

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Section: Ple and Pl Spectra Of Zno-cazo:xeu 3+ And Zno:15eu 3+ Phosph...mentioning

confidence: 99%

“…τ 1 , τ 2 are the lifetimes and A 1 and A 2 are fitting constants and these values are given in table 4. The average lifetime values could be calculated using the expression [11]:…”

Section: Ple and Pl Spectra Of Zno-cazo:xeu 3+ And Zno:15eu 3+ Phosph...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study

Singh¹,

Mishra²,

Bahadur³

2023

Phys. Scr.

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“…Chen et al prepared Sm 3+ doped Ca 2 NaZn 2 V 3 O 12 phosphor by solid state reaction method and found the color tunabillity by tuning the Sm 3+ ion concentration under 365 nm excitation 15 . Lohia et al reported Eu 3+ doped BaZnO 2 phosphor and studied their photoluminescence emission under different excitation wavelengths (275, 370, 395 & 467 nm) in which the color was found to tune from whitish to red via orange one 16 . The multicolor tunable emission has been seen by many researchers via energy transfer from sensitizer to activator 17 , 18 .…”

Section: Introductionmentioning

confidence: 99%

Multicolor tunable emission through energy transfer in Dy3+/Ho3+ co-doped CaTiO3 phosphors with high thermal stability for solid state lighting applications

Singh,

Mishra,

Rai

2023

Sci Rep

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The exploration of multicolor emitting phosphors with single phase is extremely important for n-UV chip excited LED/WLED’s and multicolor display devices. In this paper, Dy3+, Ho3+ singly doped and Dy3+/Ho3+ co-doped CaTiO3 phosphor materials have been synthesized by solid state reaction method at 1473 K. The synthesized materials were characterized by XRD, FE-SEM, EDX, FTIR, PL and lifetime measurements. The PL emission spectra of Dy3+ doped CaTiO3 phosphors give intense blue and yellow emissions under UV excitation, while the PL emission spectra of Ho3+ doped CaTiO3 phosphor show intense green emission under UV/blue excitations. Further, to get the multicolor emission including white light, Dy3+ and Ho3+ were co-doped simultaneously in CaTiO3 host. It is found that alongwith colored and white light emissions, it also shows energy transfer from Dy3+ to Ho3+ with 367 nm and from Ho3+ to Dy3+ under 362 nm excitations. The energy transfer efficiency is found to be 67.76% and 69.39% for CaTiO3:4Dy3+/3Ho3+ and CaTiO3:3Ho3+/5Dy3+ phosphors, respectively. The CIE color coordinates, CCT and color purity of the phosphors have been calculated, which show color tunability from whitish to deep green via greenish yellow color. The lifetime of 4F9/2 level of Dy3+ ion and 5S2 level of Ho3+ ion is decreased in presence of Ho3+ and Dy3+ ions, respectively. This is due to energy transfer from Dy3+ to Ho3+ ions and vice versa. A temperature dependent photoluminescence studied of CaTiO3:4Dy3+/2Ho3+ phosphor show a high thermal stability (82% at 423 K of initial temperature 303 K) in the temperature range 303–483 K with activation energy 0.17 eV. The PLQY are 30%, 33% and 35% for CaTiO3:4Dy3+, CaTiO3:4Dy3+/2Ho3+ and CaTiO3:3Ho3+ phosphors, respectively. Hence, Dy3+, Ho3+ singly doped and Dy3+/Ho3+ co-doped CaTiO3 phosphor materials can be used in the field of single matrix perovskite color tunable phosphors which may be used in multicolor display devices, n-UV chip excited LED/WLED’s and photodynamic therapy for the cancer treatment.

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Crystal Structure Induced Enhanced Afterglow Luminescence from Rare‐Earth Ion Doped Strontium Silicate Phosphors

2021

Self Cite

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An orange-red (∼ 610 nm) emitting Sr 3 SiO 5 :Eu 2 + ,Zn 2 + ,Dy 3 + long afterglow phosphor was synthesized using high temperature (1100°C-1500°C) based solid-state reaction method under controlled reducing atmosphere. X-ray diffraction (XRD) study confirms the tetragonal lattice structure having space group P4/ncc. Scherrer's size plot and Williamson-Hall methods have been applied to study the particle size distribution and inherent strain, respectively, using crystallographic data obtained from XRD patterns. Electron microscopy images showed the surface morphology with an average crystallite size of 0.412 μm. Furthermore, detailed luminescence study was performed to observe photoluminescence (PL) and afterglow characteristics. An optimal PL emission peak was registered at ∼ 610 nm when the phosphor was excited by visible blue (∼ 465 nm) light, which is due to the transitions from 4f 6 5d 1 to 4f 7 energy levels of Eu 2 + ions. The enhanced afterglow property of > 20 minutes has been achieved for dark-adapted human eyes, which could be utilized for designing strategic markings and signage boards that could glow in dark.

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Novel multi-wavelength excitable single-component phosphor system for application in white-LEDs

Cited by 14 publications

References 34 publications

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study

Multicolor tunable emission through energy transfer in Dy3+/Ho3+ co-doped CaTiO3 phosphors with high thermal stability for solid state lighting applications

Crystal Structure Induced Enhanced Afterglow Luminescence from Rare‐Earth Ion Doped Strontium Silicate Phosphors

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Novel multi-wavelength excitable single-component phosphor system for application in white-LEDs

Cited by 14 publications

References 34 publications

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu3+ over single phase ZnO:xEu3+ phosphors: a comparative study

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu3+ over single phase ZnO:xEu3+ phosphors: a comparative study

Multicolor tunable emission through energy transfer in Dy3+/Ho3+ co-doped CaTiO3 phosphors with high thermal stability for solid state lighting applications

Crystal Structure Induced Enhanced Afterglow Luminescence from Rare‐Earth Ion Doped Strontium Silicate Phosphors

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Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study

Excitation wavelength dependent color tunability, white light generation and enhanced optical emission in mixed phase ZnO–CAZO:xEu³⁺ over single phase ZnO:xEu³⁺ phosphors: a comparative study