Structural Confinement for Cr³⁺ Activators toward Efficient Near-Infrared Phosphors with Suppressed Concentration Quenching

Chemistry of Materials, Journal Year: 2021, Volume and Issue: 33(10), P. 3621 - 3630

Published: May 4, 2021

Trivalent chromium ion-doped near-infrared (NIR) phosphors have been widely studied due to their tunable emission wavelengths and broad applications. High Cr3+ concentration can improve absorption efficiency but generally results in low intensity the quenching effect. Herein, we report a series of efficient NIR with suppressed quenching, Sr9M1–x(PO4)7:xCr3+ (M = Ga, Sc, In, Lu), showing broadband ranging from 700 1100 nm peaking at 850 upon 485 light excitation. The peak position is almost independent type M ion dopant content, has little influence on luminescence thermal indicating that [MO6] octahedra are rigid enough keep octahedral volumes average M3+–O2– distances nearly constant owing formation framework structure substitution. intensities monotonously increase content increasing 0 80% Sr9Cr(PO4)7 still maintains 84.23% Sr9Ga0.2(PO4)7:0.8Cr3+ phosphor, behavior slightly dependent x; these effects be attributed energy transfer structural confinement optimal sample, Sr9Ga0.2(PO4)7:0.8Cr3+, an internal/external quantum 66.3%/29.9%. Finally, fabricate phosphor-conversion light-emitting diode demonstrate its applications nondestructive examination medical fields.

Language: Английский

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Efficient and Broadband LiGaP₂O₇:Cr³⁺ Phosphors for Smart Near‐Infrared Light‐Emitting Diodes

Laser & Photonics Review, Journal Year: 2021, Volume and Issue: 15(11)

Published: Oct. 11, 2021

Abstract Broadband near‐infrared (NIR) phosphor‐converted (pc) LED is promising next‐generation tiny light source for smart and broadband NIR spectroscopy technology. However, phosphors suffer from challenges in terms of low quantum efficiency bandwidth. By selecting a host that has big bandgap weakening coupling effect among Cr 3+ , novel LiGaP 2 O 7 :Cr (LGAP:Cr ) phosphor high external (28.3%) discovered. Under ≈450 nm excitation, LGAP:Cr shows broad emission 700 to 1100 with bandwidth ≈170 nm. Importantly, the fabricated pcLED demonstrates bright an excellent performance night vision. The results promise use high‐performance employs only one blue chip.

Language: Английский

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An Ultra-Broadband Near-Infrared Cr³⁺-Activated Gallogermanate Mg₃Ga₂GeO₈ Phosphor as Light Sources for Food Analysis

ACS Applied Electronic Materials, Journal Year: 2019, Volume and Issue: 1(6), P. 1046 - 1053

Published: May 31, 2019

A detailed nondestructive analytical method for quantitative food analysis was established by using a self-fabricated NIR-LED light source combined with Mg3Ga2GeO8 (MGGO) phosphor and blue LED chip in one package, which can be integrated into smartphones. The of MGGO:Cr3+ exhibits ultra-broadband NIR emission the range 650–1200 nm, matches well overtones molecular vibrations (e.g., O–H, C–H, N–H) presented composition. crystal structure MGGO investigated powder XRD Rietveld refinements, HRTEM images, corresponding SAED. Luminescence properties based on different Cr3+ ions positions were according to Gaussian peak fitting. Owing response organic elements, working curves between absorbance water content as sugar degree pears bananas plotted. Then reliability veracity evaluated (R2 = 0.9988). All results suggest that has potential application sources smartphones analysis.

Language: Английский

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Broadband Near-Infrared Emitting Ca₂LuScGa₂Ge₂O₁₂:Cr³⁺ Phosphors: Luminescence Properties and Application in Light-Emitting Diodes

Inorganic Chemistry, Journal Year: 2020, Volume and Issue: 59(18), P. 13481 - 13488

Published: Sept. 2, 2020

In recent years, the demand for near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) has increased rapidly, leading to more and attention being paid research of broad-band phosphors. this work, Cr3+-doped Ca2LuScGa2Ge2O12 (CLSGG:Cr3+) phosphors with NIR emission were prepared through traditional high-temperature solid-state reactions. The crystal structures analyzed by X-ray diffraction (XRD) Rietveld refinement. photoluminescence excitation (PLE) spectra synthesized CLSGG:Cr3+ exhibit a strong absorption band in 400-500 nm region, which matches well blue-light-emitting chip. (PL) show ranging from 650 1100 full width at half-maximum (fwhm) about 150 nm. At 423 K, integrated intensity CLSGG:0.02Cr3+ is 59% that room temperature. A pc-LED device was fabricated combining mixture as-synthesized phosphor silicone 460 Under driving current 100 mA, output power can achieve 1.213 mW, indicating as-prepared are promising applications.

Language: Английский

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A General Ammonium Salt Assisted Synthesis Strategy for Cr³⁺‐Doped Hexafluorides with Highly Efficient Near Infrared Emissions

Advanced Functional Materials, Journal Year: 2021, Volume and Issue: 31(36)

Published: June 24, 2021

Abstract The discovery of highly efficient broadband near infrared (NIR) emission material is urgent and crucial for constructing NIR lighting sources emerging applications. Herein, a series hexafluorides A 2 BMF 6 :Cr 3+ (A = Na, K, Rb, Cs; B Li, M Al, Ga, Sc, In) peaking at ≈733–801 nm with full width half maximum (FWHM) ≈98–115 are synthesized by general ammonium salt assisted synthesis strategy. Benefiting from the pre‐ammoniation trivalent metal sources, Cr can be more efficiently doped into simultaneously prevent generation competitive phase. Particularly, Na 3 ScF (λ em 774 nm, FWHM ≈ 108 nm) optimal ‐doping concentration 35.96% shows high internal quantum efficiency 91.5% an external ≈40.82%. emitting diode (LED) device output power ≈291.05 mW 100 mA driven current photoelectric conversion 20.94% fabricated. strategy opens up new avenues exploration ‐doped phosphors, as‐obtained record demonstrates LED

Language: Английский

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