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A series of novel yellow-emitting antimonate-based Mg2InSbO6:xDy3+ (x = 0.5, 1, 2, 10, 15, and 25 mol%) phosphors was firstly synthesized by a solid-state reaction. The crystal structure, X-ray diffraction (XRD), photoluminescence (PL) properties, and the thermal quenching behaviours of prepared Mg2InSbO6:Dy3+ samples were exhaustively studied. The Mg2InSbO6 lattice has a trigonal crystal system, which possesses the R 3 ¯ (#148) space group. The as-prepared Mg2InSbO6:Dy3+ phosphors show a bright yellow emission peak at 572 nm under near-ultraviolet (n-UV) 349 nm excitation, which is attributed to the 4F9/2–6H13/2 transition of Dy3+. The optimum product is Mg2InSbO6:10 mol% Dy3+ with the estimated Rc = 13.05 Å. The optimum sample Mg2InSbO6:10 mol% Dy3+ exhibits abnormal thermal quenching phenomenon. The emission intensity reaches a maximum at 420 K. The fluorescence lifetime of Mg2InSbO6:10 mol% Dy3+ phosphor is measured to be 0.416 ms. Besides, the CIE chromaticity coordinates of Mg2InSbO6:xDy3+ (x = 0.5–25 mol%) phosphors change slightly, which possess low correlated color temperature (CCT) and high color purity. All findings suggest that Mg2InSbO6:Dy3+ samples can serve as white emission candidates for white light-emitting diodes (w-LEDs). [ABSTRACT FROM AUTHOR]

A series of double-perovskite orange–red-emitting Ca(3−2x)SmxNaxTeO6 (x = 0.01–0.25) phosphors have been synthesized via high-temperature method. The single-phase and orthorhombic structure of Ca3TeO6:Sm3+, Na+ phosphors was confirmed by X-ray powder diffraction. Under 405 nm excitation, Ca3TeO6:Sm3+, Na+ phosphors emitted a series of orange–red emission due to the transition of Sm3+ from 4G5/2 to 6HJ/2 (J = 5, 7, 9, and 11). The optimal Sm3+-doping concentration of Ca(3−2x)SmxNaxTeO6 (x = 0.01–0.25) was x = 0.10. The thermal-quenching temperature of Ca3TeO6:0.10Sm3+, 0.10Na+ phosphor was above 480 K. A white light-emitting diode (w-LED) based on 410 nm UV chip was successfully fabricated, and it presented a good correlated color temperature and a high color-rendering index (Ra). Therefore, orange–red-emitting Ca3TeO6:Sm3+, Na+ phosphors have potential applications in UV-based w-LEDs. [ABSTRACT FROM AUTHOR]

An intense reddish-orange phosphor, Eu 2 SiS 4 :Er 3+ , was developed. The photoluminescence excitation and emission spectra, the lifetime, and the concentration effect are investigated. The results show that an efficient energy transfer occurs from Eu 2+ to Er 3+ , and its efficiency is about 81.0%. The phosphors exhibit an efficient broad absorption band and give reddish-orange emitting light with higher color purity. These results demonstrate that Er 3+ ion with low 4f - 4f absorption efficiency can play a role of activator in narrow reddish-orange emitting phosphor, potentially useful in n-UV/blue GaN-based LED through efficient energy feeding by a strong excitation band of Eu 2+ . [ABSTRACT FROM AUTHOR]

A novel broadband sensitized near-infrared emitting phosphor, Eu 2 SiS 4 :Er 3+ , was developed as promising solar spectral converter for Si solar cells. Eu 2 SiS 4 :Er 3+ has broadband absorptions ranging from 250 nm to 550 nm which can efficiently facilitate the UV-green part of the solar photon flux spectrum and exhibits intense NIR emission of Er 3+ , perfectly matching the maximum spectral response of Si solar cells. The NIR integrated emission intensity of Eu 2 SiS 4 :0.02Er 3+ is 6.14 times as intense as that of a dual-mode solar spectral converter CaLaGa 3 S 6 O:0.01Ce 3+ , 0.06Pr 3+ . These results demonstrate that Eu 2 SiS 4 :Er 3+ phosphor is a promising candidate used as solar spectral converter. [ABSTRACT FROM AUTHOR]

Novel double perovskite Sr 2 InTaO 6 :Sm3+ phosphors were synthesized by the high-temperature solid-state reaction. The phase purity, luminescent properties, and thermal stability were systematically investigated in this work. When monitoring the emission peak at 649 nm, Sr 2 InTaO 6 :Sm3+ phosphors present an absorption band due to the O2−→Sm3+ charge transfer. Under 407 nm excitation, Sr 2 InTaO 6 :5 mol%Sm3+ phosphor presents four emission peaks at 565, 603, 649, and 717 nm corresponding to the electron transition from 6G 5/2 level to 6H 5/2 , 6H 7/2 , 6H 9/2 and 6H 11/2 levels, respectively. The best doping concentration of Sr 2 InTaO 6 : x Sm3+ is optimized as x = 5 mol%. The chromaticity coordinates of Sr 2 InTaO 6 : x Sm3+ show high color stability and are located in the orange-red region. The residual luminescence intensity at 480 K reaches 86.64%, proving it has excellent thermal stability. Internal quantum efficiency (IQE) is measured as 67.1%. The prepared WLED (white light emitting diode) has a low correlation color temperature (CCT = 4853 K) and an excellent color rendering index (CRI, R a = 93) with CIE (Commission International de L′ Eclairage) coordinates (0.346, 0.349). Therefore, Sr 2 InTaO 6 :Sm3+ phosphors have excellent luminescent properties and promising application prospects. [ABSTRACT FROM AUTHOR]

The photoluminescent properties of Tb3+/Yb3+-, Ce3+/Tb3+/Yb3+-, and Eu2+/Yb3+-doped KSrPO4 are investigated by photoluminescence excitation and emission spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, novel garnet-type yafsoanite tellurate Ca 3 Zn 3 (TeO 6) 2 :Sm3+ phosphors are successfully synthesized using the traditional high-temperature solid-state reaction. The phase purity of the obtained phosphors is analyzed by X-ray diffraction and Rietveld refinement studies. Morphological variations are also observed with the different concentrations of Sm3+ ions substitution, which is analyzed using Scanning Electron Microscopy (SEM). The photoluminescent properties of the phosphors are systematically investigated. Results show that the samples display the strongest emission peak at 612 nm under the near-ultraviolet (n-UV) 409 nm excitation. This peak can be ascribed to the 4G 5/2 → 6H 7/2 transition of Sm3+. The Ca 3 Zn 3 (TeO 6) 2 :Sm3+ phosphor shows a high color purity, exhibits excellent thermal stability and good color drifting resistance. Furthermore, red and white light-emitting diodes have been successfully prepared. The white light-emitting diodes (w-LEDs) demonstrates a high color rendering index (CRI, R a) and low correlated color temperature (CCT). This study introduces a new orange-red-emitting phosphor and discusses its application in herb-growth w-LEDs. [ABSTRACT FROM AUTHOR]

A novel single-phase KCa 2 Nb 3 O 10 :Dy3+ yellow-emitting phosphor can be efficiently excited under 388 nm irradiation. [Display omitted] • KCa 2 Nb 3 O 10 :Dy3+ phosphors have been firstly synthesized using the molten-salt method. • The KCa 2 Nb 3 O 10 :Dy3+ product shows excellent thermal stability with high temperature quenching temperature. • The KCa 2 Nb 3 O 10 :Dy3+ product shows rich UV excitation band and yellow light emission. • The CIE color coordinates of prepared KCa 2 Nb 3 O 10 :Dy3+ phosphors change slightly. A series of Dy3+ doped KCa 2 Nb 3 O 10 niobate phosphors that generated yellow emission was prepared using the molten-salt method. The crystal structure, X-ray diffraction (XRD), optimal concentration, photoluminescence excitation/emission (PLE/PL), and luminescent stability of the prepared phosphors were exhaustively studied. The KCa 2 Nb 3 O 10 lattice has a perovskite-like structure, which possesses the Cmcm (No.63) space group. The KCa 2 Nb 3 O 10 :Dy3+ phosphors can be efficiently excited by n -ultraviolet (n -UV) excitation of 388 nm. Besides, KCa 2 Nb 3 O 10 :Dy3+ phosphors can emit three dominant peaks centered at 486, 577, and 662 nm, which are ascribed to the 6H J /2 (J = 15/2, 13/2, and 11/2) transitions, respectively. The optimum doping concentrations of Dy3+ ions in the KCa 2 Nb 3 O 10 host are determined to be 0.02 mol. The thermal-quenching temperature (T 0.5) for the KCa 2 Nb 3 O 10 :0.20Dy3+ sample is estimated to be above 500 K, and the calculated activation energy (E a) is 0.29 eV. Furthermore, the Commission International de I'Eclairage (CIE) color coordinates of prepared KCa 2 Nb 3 O 10 :Dy3+ phosphors change slightly. KCa 2 Nb 3 O 10 :Dy3+ phosphors possess good color purity, color stability, and low correlated color temperature (CCT). All results indicate that the KCa 2 Nb 3 O 10 :Dy3+ phosphors are suitable for white light-emitting diodes (w-LEDs) applications. [ABSTRACT FROM AUTHOR]

Abstract: A new series of blue-emitting Ce3+-doped CaLaGa3S7 thiogallate chalcogenide phosphors were synthesized by a solid-state reaction method. Their luminescence properties were investigated by photoluminescence excitation, emission spectra and lifetime. The critical dopant concentration was found to be 0.15mol of Ce3+ (R c =15Å) and the fluorescence lifetime of Ce3+ in CaLaGa3S7:0.15 Ce3+ was 12.9ns. The blue-emitting LED was fabricated by combining an InGaN chip (395nm) with a CaLaGa3S7:Ce3+ phosphor. The CIE chromaticity coordinates of the blue LED were calculated to be (0.14, 0.23). [Copyright &y& Elsevier]

Abstract: An intense green phosphor, LiSrPO4:Eu2+, Tb3+, was synthesized by high temperature solid-state reaction. The photoluminescence excitation and emission spectra, the lifetime and concentration effect are investigated in detail. The results show that an efficient non-radiative energy transfer from Eu2+ to Tb3+ occurs and its efficiency is about 66.4%. Tb3+ ions give an intense green emitting light by a strong excitation band of Eu2+ ions at 280–410nm, matching well with the dominant emission band of (n)-UV (350–420nm) LEDs. A phosphor-converted green LED was fabricated by coating the LiSrPO4:Eu2+, Tb3+ phosphor onto (n)-UV chip emitting at 370nm. These results demonstrate that Tb3+ ion with low 4f–4f absorption efficiency in (n)-UV region can play a role of activator in narrow green-emitting phosphor potentially useful in (n)-UV GaN-based LED through efficient energy feeding by allowed 4f–5d absorption of Eu2+ with high oscillator strength. [Copyright &y& Elsevier]