Stable color-tunable Ca3Y(GaO)3(BO3)4:Bi3+/Tb3+/Eu3+ phosphors for application in n-UV-pumped wLEDs

With the growing public awareness of protecting vision and prevention of hazardous effects, there is much-needed research on a “healthy” full visible spectrum under near-ultraviolet (nUV) excitation in phosphor-converted white light-emitting diodes (pc-wLEDs) to fill the “cyan gap” and avoid employing a blue LED chip. Herein, a novel series of borosilicates Ba2CaB2Si4O14 (BCBS): Ce3+/Tb3+/Sm3+/Sr2+/Na+ phosphors, presenting color-tunable photoluminescence (PL), high quantum yield (QY), and thermal stability, were designed and synthesized via a facile solid-phase reaction. The Rietveld analyses, density functional theory (DFT) simulations, and theoretical calculations of bond energy together imply the site occupations of Ce/Tb/Sm on Ba2+/Ca2+ sites with a preferred location on Ca2+ over the Ba2+ site. The broad/bright cyan-PL from BCBS: Ce under nUV excitation is associated with the allowed f–d transitions of Ce3+ and dual-site occupancies. The forbidden f–f transitions of both the green-PL of Tb and the red-PL of Sm were insensitive to the site environment and helpful to PL color regulation. The cascading Ce → Tb → Sm energy transfer is confirmed, where Tb is regarded as an energy transfer (ET) bridge to avoid the metal–metal charge transfer (MMCT) effect. The introduction of Na+ as both flux and charge compensator is for the sake of decreasing defects from heterovalent substitutions and regulating morphology. Further incorporation of Sr2+ is to modulate the lattice environments of dopants for controlling the shift of PL. Finally, as a proof-of-concept implement, a pc-wLED assembled by BCBS: Ce/Tb/Sm/Sr/Na and an nUV LED chip via a remote “capping” packaging strategy show attractive performance.

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Photoluminescence Tuning of Stable CaYGaO₄: Bi/Eu via Compositional Modulation and Crystallographic Site Engineering for nUV wLEDs

Wang,

Yao,

Lei

et al. 2024

Inorg. Chem.

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The olivine-based gallate CaYGaO4 (CYG) with unique cationic ordering, rich lattice sites, and self-photoluminescence (PL) is suitable for application as a host of phosphor. However, research in this area is still in its early stages, especially in high-quality full-spectrum white lighting. Herein, novel CYG: Bi3+/Eu3+ with a controllable PL property is designed based on energy transfer and superposition of emissions from blue self-PL, blue PL of Bi3+, and red-PL of Eu3+. Intriguingly, PL intensity and quantum efficiency could be enhanced via codoping Li+/Zn2+ separately/simultaneously because of their two intentional functions as both charge balancer and flux. Unlike self- and Eu3+ PL, Bi3+ PL is quite sensitive to the lattice environment owing to its exposed 6s2 electronic configuration and is tuned via codoping Sr2+ to regulate the nephelauxetic effect and crystal field splitting concurrently around Bi3+. Meanwhile, for further regulating the PL of Bi3+ and obtaining “warm” white light, La3+ is codoped into the phosphor via crystallographic site engineering to control the substitution trends of Bi3+ at distinct lattice sites. Finally, as a proof-of-concept, a full-spectrum phosphor-converted white-light-emitting diode device under nUV pumping with remarkable color rendering index (R a), high luminous efficiency, and chemical/thermal stability is achieved by utilizing the individual CYG:Bi/Eu/Li/Zn/Sr/La phosphor via a remote “capping” packaging method.

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Stable color-tunable Ca₃Y(GaO)₃(BO₃)₄:Bi³⁺/Tb³⁺/Eu³⁺ phosphors for application in n-UV-pumped wLEDs

Abstract: For further development of light sources, white light-emitting diodes (wLEDs), as a promising next-generation light source fabricated via combination of phosphor and LED chip, have attracted widespread attention. However, the...

Cited by 6 publications

References 44 publications

Synthesis and photoluminescence properties of novel far-red emitting garnet phosphor Y3Ga3MgSi(1-y)GeyO12:Mn4+

Synthesis and photoluminescence properties of novel far-red emitting garnet phosphor Y3Ga3MgSi(1-y)GeyO12:Mn4+

Insight into Tendentious Multisite Colonization, Site Environment Modulation, and Energy Transfer of Steady Ba₂CaB₂Si₄O₁₄: Ce/Tb/Sm/Sr/Na toward nUV-Pumped wLED Application

Photoluminescence Tuning of Stable CaYGaO₄: Bi/Eu via Compositional Modulation and Crystallographic Site Engineering for nUV wLEDs

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Stable color-tunable Ca3Y(GaO)3(BO3)4:Bi3+/Tb3+/Eu3+ phosphors for application in n-UV-pumped wLEDs

Abstract: For further development of light sources, white light-emitting diodes (wLEDs), as a promising next-generation light source fabricated via combination of phosphor and LED chip, have attracted widespread attention. However, the...

Cited by 6 publications

References 44 publications

Synthesis and photoluminescence properties of novel far-red emitting garnet phosphor Y3Ga3MgSi(1-y)GeyO12:Mn4+

Synthesis and photoluminescence properties of novel far-red emitting garnet phosphor Y3Ga3MgSi(1-y)GeyO12:Mn4+

Insight into Tendentious Multisite Colonization, Site Environment Modulation, and Energy Transfer of Steady Ba2CaB2Si4O14: Ce/Tb/Sm/Sr/Na toward nUV-Pumped wLED Application

Photoluminescence Tuning of Stable CaYGaO4: Bi/Eu via Compositional Modulation and Crystallographic Site Engineering for nUV wLEDs

Contact Info

Product

Resources

About

Stable color-tunable Ca₃Y(GaO)₃(BO₃)₄:Bi³⁺/Tb³⁺/Eu³⁺ phosphors for application in n-UV-pumped wLEDs

Insight into Tendentious Multisite Colonization, Site Environment Modulation, and Energy Transfer of Steady Ba₂CaB₂Si₄O₁₄: Ce/Tb/Sm/Sr/Na toward nUV-Pumped wLED Application

Photoluminescence Tuning of Stable CaYGaO₄: Bi/Eu via Compositional Modulation and Crystallographic Site Engineering for nUV wLEDs