High Quantum Yield Gd_4.67Si₃O₁₃:Eu³⁺ Red-Emitting Phosphor for Tunable White Light-Emitting Devices Driven by UV or Blue LED

Abstract

Eu3+-activated oxide components appear as a kind of rare-earth red phosphors that can be used for warm white light-emitting diode (LEDs). At present, it is still a challenge to synthesize oxide-component phosphors with high photoluminescence quantum yields compared to those of nitride and fluoride red phosphors. Herein, we propose a kind of Eu3+-activated Gd4.67Si3O13 rare-earth silicate phosphor by the convenient high-temperature solid reaction method. These designed phosphors can be effectively excited by either 394 nm near-ultraviolet light or 465 nm blue light and then emit red light at a dominant wavelength of 615 nm. Particularly, for the optimal Eu3+-concentration-activated Gd3.67EuSi3O13 phosphor, photoluminescence quantum yields are measured to be above 80%, which is superior to that of the general rare-earth oxide salt phosphor and comparable to that of commercial rare-earth nitride red phosphors such as Ca-α-SiAlON:Eu2+ (QY = 70.5%) and CaAlSiN3:Ce3+ (QY = 80%). Packaged with commercial yellow phosphor Ce3+:YAG and UV or blue LED chip, our red component serves to improve the CRI and CCT for the tunable white light-emitting devices. Moreover, the phosphor has good thermal cycling stability with a thermal-quenching activation energy of 0.28912 eV. Finally, the temperature-dependent properties make the Gd4.67Si3O13:Eu3+ phosphors have potential application in optical temperature measurement systems. The maximum relative sensitivity S r is found to be 1.05 × 10–2 K–1 at 456 K.

Dazzling Red-Emitting Europium(III) Ion-Doped Ca2LaHf2Al3O12 Garnet-Type Phosphor Materials with Potential Application in Solid-State White Lighting

“…A broad band in the 230–285 nm spectral region with a maximum at 265 nm and a series of sharp peaks in the 300–500 nm wavelength range were simultaneously observed in the excitation spectrum. The former broad band was ascribed to the Eu 3+ –O 2– charge transfer band, while the later sharp peaks at 320, 364, 380, 394, 417, and 465 nm were attributed to the 7 F 0 → 5 H 3 , 7 F 0 → 5 D 4 , 7 F 0 → 5 L 7 , 7 F 0 → 5 L 6 , 7 F 0 → 5 D 3 , and 7 F 0 → 5 D 2 transitions of Eu 3+ ions, respectively. , When Ca 2 LaHf 2 Al 3 O 12 :50%Eu 3+ was excited by 394 nm light, it produced four intense red emission peaks at 592, 614, 659, and 711 nm with the highest intensity at 614 nm, and these red emissions originated from the 5 D 0 → 7 F 1 , 5 D 0 → 7 F 2 , 5 D 0 → 7 F 3 , and 5 D 0 → 7 F 4 transitions of Eu 3+ ions, respectively. − Under daylight, the Ca 2 LaHf 2 Al 3 O 12 :50%Eu 3+ phosphor showed white body color, but it exhibited dazzling red luminescence upon exposure to 365 nm light (Figure b). The CIE chromaticity coordinates (0.6419, 0.3575) for Ca 2 LaHf 2 Al 3 O 12 :50%Eu 3+ were plotted in the CIE chromaticity diagram shown in Figure b.…”

A Review on Optical Applications, Prospects, and Challenges of Rare-Earth Oxides

“…Moreover, Dy 3+ shows 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions in the visible region that are influential for a yellow/blue emission and ideal white light generation. ,, Table demonstrates various studies for efficient white light generations exploiting RE ions. Figure shows various interesting properties of Dy 3 + -doped heavy metal germanium tellurite (HGT) glasses containing Ag nanoparticles, and Figures and illustrate promising properties for Gd 3.67 EuSi 3 O 13 phosphor-fabricated LEDs …”

“…(a, b) Photoluminescence variation of the Gd 3.67 EuSi 3 O 13 phosphor at different temperatures (excited at 394 nm), (c) depiction of the allowed pathways for thermal quenching, (d) normalized emission intensity for the same phosphor with different temperatures, (e) graph for ln­( I 0 / I – 1) vs 1/ k B T and (f) temperature–recycle analysis. Reproduced from . Copyright 2021 American Chemical Society.…”

“…(a) Photoluminescence intensity ratio of Gd 3.67 EuSi 3 O 13 phosphor with respect to temperature, (b) absolute sensitivity ( S a ), and relative sensitivity ( S r ) calculation from 300 to 510 K, (c, d) color coordinates, photographs, and electroluminescent spectra of the fabricated LEDs using the same phosphor under 395 nm (c) and 460 nm (d) excitation. Reproduced from ref . Copyright 2021 American Chemical Society.…”

“…2 O 3 + (27.8−x)B 2 O 3 + 40SiO 2 + xCe 2 O 3 + 0.2Tb 2 O 3 (0 ≤ x ≤ 1.0) Rao et 3 + 10CaO + 10SiO 2 + (55−x)B 2 O 3 + xDy 2 O 3 , where x = 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, and 2.5 mol %. https://doi.org/10.1021/acsaelm.1c00682interesting properties of Dy 3+ -doped heavy metal germanium tellurite (HGT) glasses containing Ag nanoparticles,78 and Figures2 and 3illustrate promising properties for Gd 3.67 EuSi 3 O 13 phosphor-fabricated LEDs 79. 4.1.2.…”