Synthesis and Luminescence Properties of Novel Ce³⁺- and Eu²⁺-Doped Lanthanum Bromothiosilicate La₃Br(SiS₄)₂ Phosphors for White LEDs

Abstract

Novel Ce(3+)- and Eu(2+)-doped lanthanum bromothiosilicate La3Br(SiS4)2:Ce(3+)and La3Br(SiS4)2:Eu(2+) phosphors were prepared by solid-state reaction in an evacuated and sealed quartz glass ampule. The La3Br(SiS4)2:Ce(3+) phosphor generates a cyan emission upon excitation at 375 nm, whereas the La3Br(SiS4)2:Eu(2+) phosphor could be excited with extremely broad range from UV to blue region (300 to 600 nm) and generates a reddish-orange broadband emission centered at 640 nm. In addition, thermal luminescence properties of La3Br(SiS4)2:Ce(3+)and La3Br(SiS4)2:Eu(2+) phosphors from 20 to 200 °C were investigated. The combination of a 450 nm blue InGaN-based LED chip with the red-emitting La3Br(SiS4)2:Eu(2+) phosphor, and green-emitting BOSE:Eu(2+) commercial phosphor produced a warm-white light with the CRI value of ∼95 and the CCT of 5,120 K. Overall, these results show that the prepared phosphors may have potential applications in pc-WLED.

Site selective substitution and its influence on photoluminescence properties of Sr0.8Li0.2Ti0.8Nb0.2O3:Eu3+ phosphors

“…1,2 The eld of solid state lighting applications like phosphor converted WLEDs is in need of new thermally and chemically stable high quantum yield red phosphors which absorb UV and visible radiations for producing white light of appropriate color rendering index (CRI) and correlated color temperature (CCT). 3 The Eu 3+ ion is an essential activator for many inorganic lattices to produce orange-red emission by the transitions 5 D 0 / 7 F J , J ¼ 0, 1, 2, 3. 4 Eu 3+ can also be used as a structural probe since its absorption and emission spectrum depends on its site symmetry in the host lattice.…”

Tuning of luminescence properties by controlling an aid-sintering additive and composition in Na(Ba/Sr/Ca)PO4:Eu2+ for white LEDs

“…The nal prole Rfactors, R wp , R p , and c 2 obtained were 8.62%, 6.19% and 1.539, respectively, which suggested that the pure NaCaPO 4 :0.01Eu 2+ with 0.03NaCl was successfully synthesized. NaCaPO 4 was indexed to an orthorhombic crystal system and space group Pnam (a ¼ 0.6797 nm, b ¼ 0.9165 nm, c ¼ 0.5406 nm, and V ¼ 0.3368 nm 3 ). The cell parameters and volume of NaCaPO 4 :0.01Eu 2+ with 0.03NaCl were a ¼ 0.680 nm, b ¼ 0.916 nm, c ¼ 0.542 nm, and V ¼ 0.3376 nm 3 , which are larger than those of NaCaPO 4 , indicating that Eu 2+ was doped into the host.…”

“…NaCaPO 4 was indexed to an orthorhombic crystal system and space group Pnam (a ¼ 0.6797 nm, b ¼ 0.9165 nm, c ¼ 0.5406 nm, and V ¼ 0.3368 nm 3 ). The cell parameters and volume of NaCaPO 4 :0.01Eu 2+ with 0.03NaCl were a ¼ 0.680 nm, b ¼ 0.916 nm, c ¼ 0.542 nm, and V ¼ 0.3376 nm 3 , which are larger than those of NaCaPO 4 , indicating that Eu 2+ was doped into the host. The crystal structure of NaCaPO 4 viewed down the b-axis and the coordination polyhedron was composed of a Na/Ca/P atomic site, as shown in Fig.…”

“…Nowadays, white light-emitting diodes (LED) have attracted signicant attention as next generation lighting devices due to their advantages of energy saving and long lifetime. [1][2][3][4][5][6][7] To date, most commercial white LEDs have been fabricated via a combination of blue LED chips and yellow emitting Y 3 Al 5 O 12 :Ce 3+ phosphors. However, these white LEDs exhibit a low color rendering index (<75) and a high correlated color temperature ($7750 K) due to the lack of a red component.…”

Li+ Ion Induced Full Visible Emission in Single Eu2+‐Doped White Emitting Phosphor: Eu2+ Site Preference Analysis, Luminescence Properties, and WLED Applications

“…Compared with the traditional light source, it has the advantages of high brightness, environmental friendliness, long duration, and energy saving. [ 2 ] Nowadays, the universal method for obtaining white light is to combine a Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ) yellow phosphor with an InGaN blue LED chip. [ 3 ] Meanwhile, this approach suffers from poor color‐rendering ( R a < 75) and high correlated color temperatures (CCT > 4500 K) due to the lack of a red spectral component.…”