Broadband NIR Phosphor Ca₂LuScAl₂Si₂O₁₂:Cr³⁺ for NIR LED Applications

Advanced Optical Materials, Год журнала: 2022, Номер 10(24)

Опубликована: Окт. 26, 2022

Abstract Near‐infrared phosphor‐converted light‐emitting diodes (NIR pc‐LEDs) have promising applications in food analysis, night vision imaging, and biological probes. Developing NIR phosphors with broadband emission high efficiency has attracted immense interest. Herein, a novel phosphor Ca 2 LuScAl Si O 12 :Cr 3+ (CLSAS:Cr ) is reported for the first time. Under excitation of 442 nm light, CLSAS:Cr shows from 600 to 900 full width at half maximum (FWHM) 142 nm, benefiting emissions two Cr centers CLSAS, which proved by spectra decay curves. The internal quantum (IQE) 73.7% achieved and, 423 K, intensity maintains 76% value room temperature. Combining 450 blue chip, pc‐LED fabricated demonstrated fast imaging veins human palm fist, as well objects.

Язык: Английский

---

Mechanoluminescence and Photoluminescence Heterojunction for Superior Multimode Sensing Platform of Friction, Force, Pressure, and Temperature in Fibers and 3D‐Printed Polymers

Advanced Materials, Год журнала: 2023, Номер 35(40)

Опубликована: Июль 3, 2023

Endowing a single material with various types of luminescence, that is, exhibiting simultaneous optical response to different stimuli, is vital in fields. A photoluminescence (PL)- and mechanoluminescence (ML)-based multifunctional sensing platform built by combining heterojunctioned ZnS/CaZnOS:Mn2+ mechano-photonic materials using 3D-printing technique fiber spinning. ML-active particles are embedded micrometer-sized cellulose fibers for flexible devices capable emitting light driven mechanical force. Individually modified 3D-printed hard units exhibit intense ML deformation, such as impact friction, also fabricated. Importantly, they allow low-pressure up ≈100 bar, range previously inaccessible any other technique. Moreover, the developed manometer based on PL demonstrates superior high-pressure sensitivity ≈6.20 nm GPa-1 . Using this platform, four modes temperature detection can be achieved: excitation-band spectral shifts, emission-band bandwidth broadening, lifetime shortening. This work supports possibility mass production optoelectronic parts integrated scientific industrial tools apparatus.

Язык: Английский

---

Intervalence charge transfer of Cr3+-Cr3+ aggregation for NIR-II luminescence

Light Science & Applications, Год журнала: 2023, Номер 12(1)

Опубликована: Июль 25, 2023

The increasing demand for high-contrast biological imaging, non-destructive testing, and infrared night vision can be addressed by the development of high-performance NIR light-emitting materials. Unlike lanthanide (Ln3+) with sharp-line multiplets isolated Cr3+ NIR-I emission, this study reports first-ever NIR-II broadband luminescence based on intervalence charge transfer (IVCT) Cr3+-Cr3+ aggregation in gallate magentoplumbite. In particular, LaMgGa11O19:0.7Cr3+ exhibits dual-emission (NIR-I, 890 nm NIR-II, 1200 nm) a full width at half maximum (FWHM) 626 under 450 blue LED excitation. Moreover, anti-thermal quenching behavior (432% @ 290 K), attributed to energy among multiple centers. Cryogen absorption spectra, lifetimes decay (2.3 ms), electron paramagnetic experiments reveal → Cr2+-Cr4+ IVCT transition. application imaging as an optical contrast agent, is demonstrated. This work provides new insights into UV-NIR excitation aggregation.

Язык: Английский

---

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

Advanced Optical Materials, Год журнала: 2023, Номер 11(21)

Опубликована: Июнь 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.

Язык: Английский

---

A multi-centre activated single-phase white light phosphor with high efficiency for near-UV based WLEDs

Inorganic Chemistry Frontiers, Год журнала: 2023, Номер 10(14), С. 4230 - 4240

Опубликована: Янв. 1, 2023

A single-phase white light phosphor, Gd 2 Sr 3 B 4 O 12 :Ce 3+ ,Tb ,Sm , with balanced and preferable comprehensive performances has been developed by energy transfer, suggesting its potential value in the applications of WLEDs.

Язык: Английский

---

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

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(23), С. 30185 - 30195

Опубликована: Май 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.

Язык: Английский

---

Full-color, time-valve controllable and Janus-type long-persistent luminescence from all-inorganic halide perovskites

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июнь 20, 2024

Abstract Long persistent luminescence (LPL) has gained considerable attention for the applications in decoration, emergency signage, information encryption and biomedicine. However, recently developed LPL materials – encompassing inorganics, organics inorganic-organic hybrids often display monochromatic afterglow with limited functionality. Furthermore, triplet exciton-based phosphors are prone to thermal quenching, significantly restricting their high emission efficiency. Here, we show a straightforward wet-chemistry approach fabricating multimode by introducing both anion (Br − ) cation (Sn 2+ doping into hexagonal CsCdCl 3 all-inorganic perovskites. This process involves establishing new trapping centers from [CdCl 6-n Br n ] 4− and/or [Sn 2-n Cd Cl 9 5− linker units, disrupting local symmetry host framework. These halide perovskites demonstrate duration time ( > 2,000 s), nearly full-color coverage, photoluminescence quantum yield ~ 84.47%), anti-thermal quenching temperature up 377 K. Particularly, : x %Br temperature-dependent time-valve controllable time-dependent luminescence, while %Sn exhibit forward reverse excitation-dependent Janus-type luminescence. Combining experimental computational studies, this finding not only introduces local-symmetry breaking strategy simultaneously enhancing lifetime efficiency, but also provides insights dynamic tunability photonics, high-security anti-counterfeiting storage.

Язык: Английский

---

Ce³⁺-Activated SrLu₂Al₃ScSiO₁₂ Cyan-Green-Emitting Garnet-Structured Inorganic Phosphor Materials toward Application in Blue-Chip-Based Phosphor-Converted Solid-State White Lighting

Inorganic Chemistry, Год журнала: 2024, Номер 63(12), С. 5743 - 5752

Опубликована: Март 13, 2024

Phosphor-converted white-light-emitting diodes (WLEDs) with superhigh color rendering index (CRI) are the ongoing pursuit of next-generation solid-state lighting. One most important challenges is limited improvement in CRI on account absence a cyan component typical commercial combination. Here, bright broad-band cyan-green-emitting phosphor cubic garnet structure, SrLu2Al3ScSiO12:Ce3+ (SLASSO:Ce3+), was successfully reported, which can compensate for cavity 480–520 nm blue-green emission region. With 439 blue-light irradiation, as-fabricated SLASSO:Ce3+ yields cyan-green maximum peak positioned at 525 and an appropriate full width half-maximum (fwhm) 111 nm, capable providing more without sacrificing green emission. Meanwhile, optimal SLASSO:2%Ce3+ features CIE coordinates (0.3254, 0.5470) hue, along high internal quantum efficiency up to 93%. Additionally, thermal stability measurements different temperatures reveal that luminescence intensity proposed retains 44% its original integral 423 K respect room temperature, while also demonstrating excellent (ΔE = 5.4 × 10–3). This work shows highly efficient be utilized as potential filling gap, resulting construction high-quality warm WLED "human-centric" sunlight-like full-spectrum illumination.

Язык: Английский

---

Full-Visible-Spectrum White LEDs Enabled by a Blue-Light-Excitable Cyan Phosphor

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(42), С. 57365 - 57376

Опубликована: Окт. 12, 2024

Efficient blue-light-excitable broadband cyan-emitting phosphors may yield full-visible-spectrum white light-emitting diodes (WLEDs) with ultrahigh color rendering (Ra > 95). However, this requires closing the "cyan gap" in 480–520 nm region of visible spectrum, which is challenging. Herein, a well-performed garnet phosphor Ca2LuAlGa2Si2O12:Ce3+ (CLAGSO:Ce3+) reported. Under 430 excitation, optimal CLAGSO:5%Ce3+ compound exhibits cyan emission (peak, 496 nm; bandwidth, 102 nm) high internal quantum efficiency 85.6% and an excellent thermal resistance performance (69.1% at 423 K). Importantly, as-prepared provides sufficient enables filling well-known so-called between blue LED chip commercial Y3Al5O12:Ce3+ (YAG:Ce3+) yellow phosphor. Impressively, WLED device fabricated sample shows low correlated temperature (4053 K) index = 96.6), as well luminous efficacy (74.09 lm W–1). These results highlight importance blue-excited gap enabling human-centric warm devices for high-quality solid-state lighting.

Язык: Английский

---

A novel highly thermal-stable Ba2GdSbO6:Sm3+ phosphor with intrinsic deep-red emission for personal identification and plant cultivation LEDs

Journal of Alloys and Compounds, Год журнала: 2024, Номер 980, С. 173518 - 173518

Опубликована: Янв. 14, 2024

Язык: Английский

---