Efficient and Stable Gd₃Ga₅O₁₂:Cr³⁺ Phosphors for High‐Performance NIR LEDs

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(21)

Published: June 7, 2023

Abstract Cr 3+ ‐activated Gd 3 Ga 5 O 12 garnet (GGG:Cr ) near‐infrared (NIR) phosphors have shown promising applications in regulating plant growth. However, the low external quantum efficiency (EQE) results a wall‐plug (WPE) of phosphor‐converted light‐emitting diodes (pc)‐LEDs only ≈15%. Herein, an easy strategy to improve luminescent properties GGG:Cr phosphor is reported. Through optimization synthesized technology, EQE enhanced 43.6%. Remarkably, fabricated pc‐LEDs achieve WPE as high 34.3%. These demonstrate significant advancement development and NIR materials pc‐LED devices.

Language: Английский

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High Output Power and High Quantum Efficiency in Novel NIR Phosphor MgAlGa_0.7B_0.3O₄:Cr³⁺ with Profound FWHM Variation

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(9)

Published: Nov. 8, 2023

Abstract There is strong demand for ultraefficient near‐infrared (NIR) phosphors with adjustable emission properties next‐generation intelligent NIR light sources. Designing large full‐width at half‐maximum (FWHM) variations challenging. In this study, novel near‐ultraviolet light‐emitting diode (LED)‐excited phosphors, MgAlGa 0.7 B 0.3 O 4 :Cr 3+ (MAGBO:Cr ), three centers achieve ultra‐narrowband (FWHM = 29 nm) to ultra‐broadband 260 increasing Cr concentration. Gaussian fitting and decay time analysis reveal the alteration in FWHM, which attributed energy transfer occurring between centers. The distinct thermal quenching behaviors of are revealed through temperature‐dependent times. phosphor MAGBO:0.05Cr exhibits high stability (85%, 425 K) exceptional external quantum efficiency 68.5%. An phosphor‐converted LED (pc‐LED) fabricated using phosphor, exhibiting a remarkable output power 136 mW 600 mA pc‐LEDs. This study describes preparation highly efficient provides further understanding tunable vital high‐performance versatile applications.

Language: Английский

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Near‐Infrared Luminescent Materials Incorporating Rare Earth/Transition Metal Ions: From Materials to Applications

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(30)

Published: May 11, 2024

Abstract The spotlight has shifted to near‐infrared (NIR) luminescent materials emitting beyond 1000 nm, with growing interest due their unique characteristics. ability of NIR‐II emission (1000–1700 nm) penetrate deeply and transmit independently positions these NIR for applications in optical‐communication devices, bioimaging, photodetectors. combination rare earth metals/transition metals a variety matrix provides new platform creating chemical physical properties science device applications. In this review, the recent advancements activated by transition metal ions are summarized role spanning sensing, optoelectronics is illustrated. It started various synthesis techniques explored how earths/transition can be skillfully incorporated into matrixes, thereby endowing them discussion strategies enhancing excitation absorption efficiency, spotlighting innovations like dye sensitization surface plasmon resonance effects then extended. Subsequently, significant focus placed on functionalization Finally, comprehensive analysis challenges proposed earth/transition ion‐doped materials, summarizing insights each section provided.

Language: Английский

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Emerging Fe³⁺ Doped Broad NIR‐Emitting Phosphor Ca_2.5Hf_2.5(Ga, Al)₃O₁₂: Fe³⁺ for LWUV Pumped NIR LED

Laser & Photonics Review, Journal Year: 2024, Volume and Issue: 18(5)

Published: Jan. 22, 2024

Abstract Fe 3+ is a promising dopant for designing near‐infrared (NIR) phosphors due to its broadband emitting, non‐toxic, and inexpensive properties. However, the 4 E ( D) + A 1 G) levels of ions are independent crystal‐field parameter, spectral regulation has become huge challenge. Herein, NIR‐emitting phosphor Ca 2.5 Hf (Ga, Al) 3 O 12 : successfully developed toward long‐wave ultraviolet (LWUV) light‐pumped NIR phosphor‐converted LED (pc‐LED). Significantly, excited transition reverse Ga can be realized by simply adjusting concentration, which results in largely enhanced excitation around 410 nm matches well with commercial LWUV LED. Moreover, exhibit emission centered at 770 optimized doping content 0.01 mol%, demonstrated ascribe occupying both octahedral 4+ tetrahedral sites. Further, simple cation modulation strategy proposed break lattice symmetry enhance NIR‐emission intensity 200% as much before. Finally, pc‐LED fabricated employing , Al coating on chip, shows great potential non‐destructive inspection applications.

Language: Английский

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Unlocking Cr³⁺–Cr³⁺ Coupling in Spinel: Ultrabroadband Near-Infrared Emission beyond 900 nm with High Efficiency and Thermal Stability

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(23), P. 30185 - 30195

Published: May 31, 2024

Broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) hold promising potential as next-generation compact, portable, and intelligent NIR light sources. Nonetheless, the lack of high-performance broadband phosphors with an emission peak beyond 900 nm has severely hindered development widespread application pc-LEDs. This study presents a strategy for precise control energy-state coupling in spinel solid solutions composed MgxZn1–xGa2O4 to tune emissions Cr3+ activators. By combining crystal field engineering heavy doping, Cr3+–Cr3+ ion pair from 4T2 state is unlocked, giving rise unusual spanning 650 1400 maximum 913 full width at half-maximum (fwhm) 213 nm. Under optimal Mg/Zn ratio 4:1, sample achieves record-breaking performance, including high internal external quantum efficiency (IQE = 83.9% EQE 35.7%) excellent thermal stability (I423 K/I298 K 75.8%). Encapsulating as-obtained into prototype pc-LEDs yields overwhelming output power 124.2 mW driving current 840 mA photoelectric conversion (PCE) 10.5% 30 mA, rendering performance imaging applications.

Language: Английский

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Boosting Near‐Infrared Emission in Spinel‐Type Phosphor via Oxygen Vacancy Engineering for Versatile Application

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: April 30, 2024

Abstract Fe 3+ ‐doped MgGa 2 O 4 (MGO: ) spinel‐type near‐infrared (NIR) phosphor with non‐toxicity, outstanding thermal stability, and tunable emission has recently gained great concern owing to its wide applications. Nevertheless, the existence of detrimental defects in host forbidden d‐d transitions lead unsatisfactory luminescence efficiency, limiting commercial application. In this study, a vacancy repairing engineering been innovatively developed via F − substitution MGO: (MGOF: for significantly enhancing NIR maintaining stability. Specifically, similar radius effectively repairs intrinsic MGO, thereby prohibiting electron‐capturing effect. Meanwhile, incorporation can make lattice MGO distort break transition . Significantly, obtained MGOF: presents 16‐fold higher intensity than that More important, remain at 91.17% (363 K) 85.10% (423 K). Finally, be used night vision, non‐destructive biological tissue detection, food analysis. The proposed strategy certainly stimulate some new thoughts concepts designing high‐performance phosphors wider

Language: Английский

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Developing the Na₂CaZr₂Ge₃O₁₂:Cr³⁺ Garnet Phosphor for Advanced NIR pc-LEDs in Night Vision and Bioimaging

Chemistry of Materials, Journal Year: 2024, Volume and Issue: 36(9), P. 4654 - 4663

Published: May 1, 2024

Materials emitting near-infrared (NIR) light play a crucial role in the development of phosphor-converted light-emitting diodes (pc-LEDs) for applications ranging from fundamental science like spectroscopic analysis to highly applied uses night vision and biological imaging. One class materials that has garnered significant interest these technical spaces is Cr3+-activated garnets due their high efficiency ability operate at relatively temperatures. However, limited emission beyond 800 nm impedes use as optimal blue LED-pumped NIR-emitting materials. In this study, we present new garnet-type NIR phosphor, Na2CaZr2Ge3O12:Cr3+, addresses challenge─the material exhibits long-wavelength (λem,max = 832 nm) good thermal quenching resistance while maintaining an excellent internal quantum (IQE 98%). These properties are attributed crystal environment reconstruction, where structure distortion coupled weak field, which uncommon most rigid phosphors. Furthermore, fabricated pc-LED devices using demonstrate superior performance compared with employing well-known efficient phosphors operating range. The source subsequently demonstrated spanning vision, bioimaging, nondestructive analysis. This study not only provides insights into luminescence garnet desirable but also highlights practical application

Language: Английский

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Phosphor‐in‐Ceramic‐Converted Laser‐Driven Near‐Infrared Light Sources for Multiple Intelligent Spectroscopy Applications

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 3, 2024

Abstract Ultrabright broadband near‐infrared (NIR) phosphor‐converted laser diode (pc‐LD) as a light source is increasingly essential for improving the sensitivity and spatial resolution of intelligent NIR spectroscopy technologies. However, performance pc‐LD greatly hindered by low external quantum efficiency (EQE) poor thermal resistance phosphor materials. Herein, highly stable phosphor‐in‐ceramic (PiC) film deposited on high conductivity substrate, in which NIR‐emitting Ca 3 MgHfGe O 12 :Cr 3+ incorporated into glass‐crystallized Ga 2 Ge ceramic matrix, along with formation new type PiC composite material efficiency, absorbance, conductivity, designed prepared. The obtained exhibits an impressive EQE 57.7%, 17.1 W m −1 K , wheel demonstrates emission exceeding 5 when excited 450 nm laser. Finally, groundbreaking electrically driven device based achieves 1.6 output, enabling multiple applications archaeology night vision imaging. This work paves way advancing sources diverse range photonic applications.

Language: Английский

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Highly Efficient and Thermally Stable Broadband NIR Phosphors with Superlong Afterglow Performance and their Multifunctional Applications

Laser & Photonics Review, Journal Year: 2024, Volume and Issue: 18(10)

Published: May 16, 2024

Abstract Near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are considered as promising next‐generation light sources for optoelectronic and biomedical applications. Nevertheless, NIR phosphors with large bandwidths, long emission peaks, high external quantum efficiencies (EQEs) valuable thermal stabilities challenging to develop. Herein, this study reports a novel gallium germanate host, Ga 3 Al Ge 2 O 13 (GAGO), bandgap rigid host lattice Cr 3+ ion doping. The blue LED excitable GAGO:0.012Cr phosphor can produce broadband maximum intensity at 816 nm full‐width half‐maximum (FWHM) of 187 nm. Notably, the also exhibits an excellent EQE 35.8% perfect stability (I 423 K /I 298 = 67.4%). Moreover, attractive afterglow duration more than 24 h is achieved in GAGO:0.004Cr phosphor. type origin traps discussed, possible persistent luminescent (LPL) mechanism proposed. Finally, pc‐LED based on fabricated. results demonstrate that obtained show great potential use night vision, nondestructive detection, bioimaging information encryption. This provides new insight into development materials efficiency, good extraordinary performance.

Language: Английский

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Cr3+-doped Na2CaSn2Ge3O12 garnet showing broadband near-infrared emission at 820 nm with zero thermal quenching and near-unity quantum yield

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 499, P. 156274 - 156274

Published: Sept. 30, 2024

Language: Английский

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