Rapid synthesis and enhancement in down conversion emission properties of BaAl2O4:Eu2+,RE3+ (RE3+=Y, Pr) nanophosphors

Sivaramaiah²,

et al. 2019

Bull Mater Sci

A BaAl 2 O 4 :Gd 3+ phosphor was successfully prepared using a combustion technique. An X-ray diffraction pattern was used to characterize the resultant phosphor, and the photoluminescence (PL) of the prepared BaAl 2 O 4 :Gd 3+ was studied. Under a 273-nm excitation, the main emission peak of the phosphor is located at 314 nm, and this is attributed to the 6 P 7/2 → 8 S 7/2 transition of Gd 3+. Electron paramagnetic resonance (EPR) spectrum appears to be U-shaped, and lines are evident at g eff ∼ 2.14, 4.56 and 6.75. The PL and EPR analyses indicate the presence of Gd as Gd 3+ in this sample.

Section: Introductionmentioning

confidence: 93%

Ultraviolet B emission from a $$\hbox {Gd}^{3+}$$ Gd 3 + -doped $$\hbox {BaAl}_{2}\hbox {O}_{4}$$

Sivaramaiah²,

et al. 2019

Bull Mater Sci

“…The high‐resolution XPS survey spectrum of the europium in CBH : Eu is shown in Figure 5b. Four peaks appear near 1124.8, 1134.9, 1154.4 and 1164.6 eV, among which the single peaks at 1124.8 and 1154.4 eV belong to 3d 5/2 and 3d 3/2 of Eu 2+ , respectively, and the single peaks at 1134.9 and 1164.6 eV belong to 3d 5/2 and 3d 3/2 of Eu 3+ , respectively [36,53,54] . Due to surface oxidation, the single peak of Eu 3+ may come from the surface of CBH : Eu.…”

Section: Resultsmentioning

confidence: 99%

Ca[B₈O₁₁(OH)₄] : Eu²⁺ – A Highly Efficient Deep Blue‐Emitting Phosphor Prepared by Low‐Temperature Self‐reduction

Liang

Wenli

Liu

2021

Chemistry A European J

Highly efficient inorganic phosphors are crucial for solid‐state lighting. In this paper, a new method of low‐temperature self‐reduction was used for preparing a highly efficient deep blue‐emitting phosphor of Ca[B8O11(OH)4] : Eu2+ (CBH : Eu2+). The crystal structure, morphology, chemical state, and photoluminescence (PL) properties of the CBH : Eu2+ phosphor have been investigated. By using the screened hybrid function (HSE06), the band gap (Eg) of CBH was calculated to be 7.48 eV, which is a necessary condition for achieving high quantum yield phosphors. The experiment results show that almost all the added raw materials of Eu3+ can be reduced to Eu2+ in CBH crystal under a non‐reducing atmosphere. The CBH : Eu2+ phosphor shows a broad excitation spectrum centered at 277 and 327 nm in the range of 220 to 400 nm, and a narrow‐band emission spectrum centered at 428 nm in the range of 400 to 500 nm, with a full width at half maximum (fwhm) of 42.35 nm. Under UV radiation, the CBH : 2 %Eu2+ exhibits high photoluminescence quantum yield (PLQY=95.0 %), high external quantum efficiency (EQE=31.1 %), and ultra‐high color purity (97.6 %). The PL intensity of CBH : 2 %Eu2+ remains 62.6 % of the initial intensity at 150 °C. Finally, the white light‐emitting diodes (WLED) fabricated by CBH : 2 %Eu2+, excited by a 365 nm chip, presents outstanding performances with a luminous efficacy (LE) of 13.9 lm/W, a color rendering index (CRI) of 89.4, and a correlated color temperature (CCT) of 5825 K. The above results show that CBH : Eu2+ can be used as a promising blue phosphor for WLED. This new method of low‐temperature self‐reduction can be applied to design and prepare other new types of highly efficient phosphors.

“…[4,5] Due to its numerous potential uses in the lighting field (fluorescent tubes, white-light emitting diodes and solid-state lasers), rare-earth ion (RE 3+ )-doped inorganic luminous materials have recently undergo substantial research in the domains of material science, physics, chemistry and life sciences. [6][7][8][9] With the advancement of nanoscience and nanotechnology, efforts are also being made to develop high-performing luminescent nanomaterials for diverse lighting applications and display technology. [10] As a result, the desire for new single-phase phosphors and highly effective energy transfer has increased substantially.…”

Section: Introductionmentioning

confidence: 99%

“…[ 4,5 ] Due to its numerous potential uses in the lighting field (fluorescent tubes, white‐light emitting diodes and solid‐state lasers), rare‐earth ion (RE 3+ )‐doped inorganic luminous materials have recently undergo substantial research in the domains of material science, physics, chemistry and life sciences. [ 6–9 ]…”

Section: Introductionmentioning

confidence: 99%

Emerging green light emission of Er³⁺‐activated single phased GdAlO₃ phosphors for lighting applications

et al. 2022

Self Cite

An erbium ion (Er3+)‐activated gadolinium aluminate (GdAlO3) nanophosphor was synthesized by utilizing urea assisted gel‐combustion method. The crystal structure along with all other crystal parameters was determined by X‐ray diffraction (XRD) patterns. The selected samples are of orthorhombic phase with Pnma space group. The agglomerated particles within nanorange have been confirmed by transmission electron microscopy (TEM) micrographs. Elemental investigation was performed by energy dispersive X‐ray spectroscopy (EDX). Photoluminescence excitation (PLE) spectrum reveals a strong excitation band corresponding to the gadolinium ion (Gd3+) (276 nm) and a band near ultraviolet (UV) absorption for Er3+ (377 nm). Strong excitation band of Gd3+ was evident for the energy transfer between Gd3+ and Er3+ ions. All the doped sampled are excited at 377 nm wavelength. The photoluminescence (PL) spectrum exhibits an intense band at 546 nm (4S3/2 → 4I15/2) which is responsible for the green emission in the processed samples. The color coordinate values define their color in the green region and correlated color temperature (CCT) values affirm their utility as a cold light source.