Achieving High Quantum Efficiency Broadband NIR Mg₄Ta₂O₉:Cr³⁺ Phosphor Through Lithium‐Ion Compensation

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(22)

Published: March 3, 2023

Ultra-efficient broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are urgently needed to improve the detection sensitivity and spatial resolution of current smart NIR spectroscopy-based techniques. Nonetheless, performance pc-LED has severely limited owing external quantum efficiency (EQE) bottleneck materials. Herein, a blue LED excitable Cr3+ -doped tetramagnesium ditantalate (Mg4 Ta2 O9 , MT) phosphor is advantageously modified through lithium ion as key efficient emitter achieve high optical output power light source. The emission spectrum encompasses 700-1300 nm electromagnetic first biological window (λmax = 842 nm) with full-width at half-maximum (FWHM) ≈2280 cm-1 (≈167 nm), achieves record EQE 61.25% detected 450 excitation Li-ion compensation. A prototype fabricated MT:Cr3+ Li+ evaluate its potential practical application, which reveals an 53.22 mW driving 100 mA, photoelectric conversion 25.09% 10 mA. This work provides ultra-efficient luminescent material, shows great promise in applications presents novel option for next-generation high-power compact sources.

Language: Английский

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Broadband Short-Wave Infrared-Emitting MgGa₂O₄:Cr³⁺, Ni²⁺ Phosphor with Near-Unity Internal Quantum Efficiency and High Thermal Stability for Light-Emitting Diode Applications

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(27), P. 32580 - 32588

Published: June 29, 2023

Blue InGaN chip-pumped short-wave infrared (SWIR) emitters have aroused tremendous attention and shown emerging applications in diverse fields such as healthcare, retail, agriculture. However, discovering blue light-emitting diode (LED)-pumped SWIR phosphors with a central emission wavelength over 1000 nm remains significant challenge. Herein, we demonstrate the efficient broadband luminescence of Ni2+ by simultaneously incorporating Cr3+ ions into MgGa2O4 lattice, sensitizer emitter. Because strong light absorption high energy transfer efficiency to Ni2+, obtained MgGa2O4:Cr3+, show intense peak at 1260 full width half maximum (FWHM) 222 under excitation light. The optimized phosphor presents an ultra-high photoluminescence quantum 96.5% outstanding thermal stability (67.9%@150 °C). A source has been fabricated through combination prepared commercial 450 LED chip, delivering radiant power 14.9 mW 150 mA input current. This work not only demonstrates feasibility developing high-power using converter technology but also new insights importance technology.

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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Near‐infrared emitting metal halide materials: Luminescence design and applications

InfoMat, Journal Year: 2024, Volume and Issue: 6(5)

Published: March 28, 2024

Abstract Near‐infrared (NIR) luminescent metal halide (LMH) materials have attracted great attention in various optoelectronic applications due to their low‐temperature solution‐processable synthesis, abundant crystallographic/electronic structures, and unique properties. However, some challenges still remain luminescence design, performance improvement, application assignments. This review systematically summarizes the development of NIR LMHs through classifying origins into four major categories: band‐edge emission, self‐trapped exciton (STE) ion defect‐related emission. The mechanisms different types are discussed detail by analyzing typical examples. Reasonable strategies for designing optimizing luminescence/optoelectronic properties summarized, including bandgap engineering, self‐trapping state chemical composition modification, energy transfer, other auxiliary such as improvement synthesis scheme post‐processing. Furthermore, prospects based on devices revealed, phosphor‐converted light‐emitting diodes (LEDs), electroluminescent LEDs, photodetectors, solar cells, x‐ray scintillators, well demonstrations related practical applications. Finally, existing future perspectives LMH critically proposed. aims provide general understanding guidance design high‐performance materials. image

Language: Английский

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Tunable Spinel Structure Phosphors: Dynamic Change in Near‐Infrared Windows and Their Applications

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(23)

Published: July 26, 2023

Abstract Applications in near‐infrared (NIR) have been explored significantly many fields, including bioimaging, night vision, plant growth, and chemical analysis. Different emission profiles are required within the same industry. Developing luminescent materials with different tuning methods is reliable for controlling NIR regions (NIR‐I, 700–1000 nm; NIR‐II, 1000–1700 nm). Spinel phosphors promising candidates due to their ability modulate crystal field. Understanding parameters that influence degree of inversion spinel compounds crucial harness variability structure. Cr 3+ Ni 2+ ideal activators NIR‐I NIR‐II emissions, respectively. However, there a need emit region when excited by visible light. Although energy transfer method combining two considered, this review focuses on types structures, discussing common strategies tune host The goal achieve desired shift broadness entire spectrum, highlighting importance spectrum practical applications.

Language: Английский

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Highly Quantum Efficient and Thermally Stable Near‐Infrared‐Emitting K‐β‐Al₂O₃:Cr³⁺ Phosphor

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(4)

Published: Aug. 31, 2023

Abstract Near‐infrared (NIR) phosphors are enablers for NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). However, fewer NIR‐emitting with both high internal/external quantum efficiency (IQE/EQE) and thermal stability discovered, which obstructs the promotion of pc‐LEDs. Herein, by partially replacing Al 3+ in K‐β‐Al 2 O 3 :2Cr Ga , photoluminescence (PL) intensity solid solution K 1+δ (Al 0.4 0.6 ) 11 17 (KA G O:Cr) phosphor is increased 2.75 1.25 times that end‐members (KAO:Cr) (KGO:Cr). The IQE/EQE optimal KA O:Cr reaches 88.9%/50.8% (77.4%@150 °C). PL enhancement due to Al/Ga‐6O octahedral volume distortion variation caused substitution 1‐y ,Ga y O:Cr), leads forbidden d–d transition being broken crystal field strength varied. Finally, a pc‐LED device fabricated based on blue chip an electro‐optical 16.3% under drive current 100 mA. Meanwhile, non‐destructive detection plant germination applications demonstrated. These results prove promising diverse applications.

Language: Английский

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Chromium Cluster Luminescence: Advancing Near‐Infrared Light‐Emitting Diode Design for Next‐Generation Broadband Compact Light Sources

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(13)

Published: Dec. 16, 2023

Abstract In modern technology devices, an energy‐saving miniature near‐infrared (NIR) light source plays a critical role in non‐destructive, non‐invasive sensing applications and further advancement of technology. This paper reports the broadband NIR luminescence Cr 3+ clusters for designing phosphor‐converted light‐emitting diodes as alternative to typical isolated centers ion pairs. Here, form intermediate spinel structure MgGa 2 O 4 by utilizing long‐chain edge‐shared octahedral dimers with shortest bond distance between cations. Electron paramagnetic magnetometry measurements confirm clusters, resulting three distinct emission centers. The formation ensures stable internal quantum efficiency (≈94%), full‐width‐half‐maximum (248 nm), thermal stability (87%), radiant flux ≈17.66 mW. work offers promising approach phosphor design enhances understanding mechanisms related structures.

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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Ultrahigh Quantum Efficiency Near-Infrared-II Emission Achieved by Cr³⁺ Clusters to Ni²⁺ Energy Transfer

Chemistry of Materials, Journal Year: 2024, Volume and Issue: 36(8), P. 3941 - 3948

Published: April 12, 2024

Increasing demand for near-infrared-II (NIR-II) light sources requires improved NIR-II phosphors. We present a series of phosphors codoped with Cr3+ and Ni2+ that possess emission an unprecedented internal quantum efficiency (IQE) 97.4%. Our study reveals energy transfer mechanism involving clusters where luminescent centers are closely matched in the intensity can be tuned through sintering temperature. The profound electron paramagnetic resonance (EPR) studies disclose interaction between Cr3+–Ni2+ pairs, further proving cause such high IQE significance clusters. This work provides promising pathways development light-emitting diodes outstanding by suggesting new source Cr3+.

Language: Английский

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