Ca₅Ga₆O₁₄:Eu³⁺: A novel phosphor with outstanding heat resistance for white light‐emitting diodes

Abstract

A novel red-emitting phosphor Ca 5 Ga 6 O 14 :Eu 3+ has been synthesized using solidstate method. The excitation and emission spectra show that the phosphor can emit the red light with the main peak at 611 nm under excitation of the 280 and 393 nm UV chip and the optimal Eu 3+ concentration is determined to be x = 0.07. Analysis of emission spectrum shows that Eu 3+ occupy the center of noninversion symmetry. With the increase of Eu 3+ doping concentration, the decay time is prolonged due to deeper energy trap arising from nonequivalent substitution. Additionally, the measured thermal stability with 0.539 eV activation energy and calculated 90.5% color purity of optimal phosphor indicate that the phosphor has an enormous application potential in w-LEDs industry.

Synergistic effects of Tb doping in long-persistent luminescence in Ca3Ga4O9: xBi3+, yZn2+ phosphors: Implications for novel phosphorescent materials

“…Ca 3 Ga 4 O 9 , and the secondary phases found in the compounds triply doped, CaGa 2 O 4 , and Ca 5 Ga 6 O 14 are all orthorhombic and belong to the cmm2, pna21, and Cmc21 space groups, respectively [ 25 , 26 ]. While Ga occupies the tetrahedral site in all three structures, the main distinctions lie in the surrounding oxygen arrangement with respect to Ca.…”

“…The synthesis conditions for all three structures are very similar. They were obtained using the same precursors (CaCO 3 and Ga 2 O 4 ) through a solid-state reaction at comparable temperatures (1200 °C for 10 h–1300 °C for 6 h and 1200 °C for 6 h, respectively) [ [25] , [26] , [27] ]. The variation lies in the stoichiometry between the starting precursors.…”

Enhanced luminescence properties of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red phosphors based on composition modulation

“…Meanwhile, the PLE spectrum contains several sharp peaks between 350 and 500 nm owing to the typical intra-4f transitions of the Eu 3+ ions. 19,36 Obviously, the two strongest peaks at 393 and 465 nm, originating from the 7 F 0 / 5 L 6 and 7 F 0 / 5 D 2 transitions of the Eu 3+ ions, respectively, can be observed, which illustrate the prepared sample can be excited by the near ultraviolet and blue LED chips effectively. 36 Upon excitation at 393 nm, several emission peaks from 550 to 750 nm, corresponding to the electronic 5 D 0 / 7 F i (i ¼ 0, 1, 2, 3, 4) transitions, are present in the PL spectrum.…”

“…19,36 Obviously, the two strongest peaks at 393 and 465 nm, originating from the 7 F 0 / 5 L 6 and 7 F 0 / 5 D 2 transitions of the Eu 3+ ions, respectively, can be observed, which illustrate the prepared sample can be excited by the near ultraviolet and blue LED chips effectively. 36 Upon excitation at 393 nm, several emission peaks from 550 to 750 nm, corresponding to the electronic 5 D 0 / 7 F i (i ¼ 0, 1, 2, 3, 4) transitions, are present in the PL spectrum. 3 The most intense emission peak at 612 nm and four other weaker emission peaks at 579, 594, 653 and 707 nm can be found, which are in good agreement with the 5 D 0 / 7 F 2 , 5 D 0 / 7 F 0 , 5 D 0 / 7 F 1 , 5 D 0 / 7 F 3 and 5 D 0 / 7 F 4 transitions of the Eu 3+ ions, respectively.…”

Sustainably Adjusting the Up-Conversion White-Emitting Luminescence Properties of GdAlO3: Er3+/Yb3+/Tm3+ Phosphors

“…Recently, the development of green and sustainable approaches have become a particularly important theme. The use of white light-emitting diodes (WLEDs) as a promising general illumination source in lighting and display applications has attracted great attention (Du et al, 2018 ; Li et al, 2018 ; Liu et al, 2019 ). There are two alternative approaches to WLEDs assembly now.…”