Enhanced luminescence and white light emission from Eu³⁺‐co‐doped K₃Ca₂(SO₄)₃Cl:Dy³⁺ phosphor with near visible ultraviolet excitation for white LEDs

Abstract

The luminescent properties of europium (Eu)- and dysprosium (Dy)-co-doped K3 Ca2 (SO4 )3 Cl halosulfate phosphors were analyzed. This paper reports the photoluminescence (PL) properties of K3 Ca2 (SO4 )3 Cl microphosphor doped with Eu and Dy and synthesized using a cost-effective wet chemical method. The phosphors were characterized by X-ray diffraction and scanning electron microscopy. The CIE coordinates were calculated to display the color of the phosphor. PL emission of the prepared samples show peaks at 484 nm (blue), 575 nm (yellow), 594 nm (orange) and 617 nm (red). The emission color of the Eu,Dy-co-doped K3 Ca2 (SO4 )3 Cl halophosphor depends on the doping concentration and excitation wavelength. The addition of Eu in K3 Ca2 (SO4 )3 Cl:Dy greatly enhances the intensity of the blue and yellow peaks, which corresponds to the (4) F9/2 → (6) H15/2 and (4) F9/2 → (6) H13/2 transitions of Dy(3+) ions (under 351 nm excitation). The Eu(3+) /Dy(3+) co-doping also produces white light emission for 1 mol% of Eu(3+) , 1 mol% of Dy(3+) in the K3 Ca2 (SO4 )3 Cl lattice under 396 nm excitation, for which the calculated chromaticity coordinates are (0.35, 0.31). Thus, K3 Ca2 (SO4 )3 Cl co-doped with Eu/Dy is a suitable candidate for NUV based white light-emitting phosphors technology.

Rare earth Eu3+/Tb3+‐doped hollow microspheres (LaPO4) and core‐shell nanocomposite luminescent materials with different transmittance (SiO2@LaPO4 Eu3+) preparation and research on luminescence performance

“…It is clear from the preceding emission spectra that selfactivated emissions of blue light from lanthanum phosphate, orange light from Eu 3+ emission, and green light from Tb 3+ characteristic emission are combined when ultraviolet excitation is used. White light can be created when the emission intensities of several components match in the right proportion [32,33].…”

Photoluminescence and electron paramagnetic resonance properties of a potential phototherapic agent: MMgF4:Gd3+ (M = Ba, Sr) sub‐microphosphors

“…The white powder samples of BaMgF 4 and SrMgF 4 compounds, which were synthesized by the co-precipitation method, were characterized by XRD (λ = 0.15405 nm). Figure 1 shows a comparison of the XRD patterns of synthesized BaMgF 4 and SrMgF 4 with the standard ICDD data. The XRD patterns of BaMgF 4 and SrMgF 4 matched well with the reported ICDD data file no.…”

“…To date, RE‐doped compounds have been used extensively in luminescence applications such as displays [e.g. plasma display devices (PDP), field emission displays (FED)], laser generation, white light‐emitting diodes (W‐LEDs), upconversion phosphors for bio‐imaging, photodynamic therapy and phototherapy lamps . Phosphors with good quantum efficiency, no toxicity and economic viability are preferred for these applications .…”

Novel low‐temperature synthesis of Y2–xO3:Eux3+ nanophosphor using combustion with thioglycerol as fuel for near‐UV light‐emitting diodes

“…The emission wavelength of Eu 3+ ions is ~615 nm, resulting from the 5 D 0 ‐ 7 F 2 electric dipole transition, and the ions also emit strongly at ~595 nm due to the 5 D 0 ‐ 7 F 1 magnetic dipole transition. The position of these emission lines in the spectrum is determined by the splitting of the activator with the host material [11, 12].…”

“…due to the 5 D 0 -7 F 1 magnetic dipole transition. The position of these emission lines in the spectrum is determined by the splitting of the activator with the host material [11,12]. Y 2 O 3 :Eu 3+ is a widely used red oxide phosphor known for its high luminescence efficiency, stability in atmospheric conditions, and absence of hazardous constituents compared to sulfide phosphors.…”