High‐Efficiency Short‐Wave Infrared Emitter Enabled by Cr³⁺–Yb³⁺ Co‐Doped Phosphor

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(16)

Published: March 14, 2024

Abstract The utilization of phosphor‐converted light‐emitting diodes (pc‐LEDs) as compact short‐wave infrared (SWIR) emitters has emerged a promising strategy for miniature SWIR spectrometers in portable devices, enabling diverse applications such nondestructive identification, bioimaging, night‐vision surveillance, and optical communication. However, discovering phosphors capable efficiently absorbing blue light emitting pure (>900 nm) remains significant challenge. Here, highly efficient thermally stable luminescence Yb 3+ upon LED excitation by employing Cr –Yb energy transfer Y 3 Ga 5 O 12 garnet is reported. prepared :Cr ,Yb phosphor exhibits intense emission spanning from 900 to 1150 nm at 438 excitation, coupled with ultra‐high internal/external quantum efficiency 80.8%/40.2% excellent thermal stability (108%@150 °C). A pc‐LED prototype fabricated incorporating the optimized commercial 450 chip, shows exceptional performance, delivering output power 92.7 mW driving current 350 mA photoelectric 21.5% 10 mA. This work opens up new avenue designing that exhibit photoluminescence demonstrating potential next‐generation high‐power sources.

Language: Английский

---

Synergy between structural rigidity and cluster defects in a bright near-infrared Cr³⁺-based phosphor for excellent thermal stability and long afterglow

Journal of Materials Chemistry C, Journal Year: 2024, Volume and Issue: 12(26), P. 9716 - 9732

Published: Jan. 1, 2024

This work investigates the important role of structural rigidity and defect related dynamics a promising garnet phosphor with robust thermal stability for efficient NIR pc-LED devices.

Language: Английский

---

Efficient broad-band NIR-II emitting phosphor Mg4Ta2O9: Ni2+ with satisfactory thermal stability of luminescence

Ceramics International, Journal Year: 2024, Volume and Issue: 50(11), P. 18647 - 18654

Published: March 5, 2024

Language: Английский

---

Directly Identifying Multiple Cr³⁺ Emitting Centers for Broad Near‐Infrared Emission in an Efficient and Near‐Zero Thermal Quenching Garnet‐Type Phosphor

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(11)

Published: Feb. 8, 2024

Abstract Cr 3+ doped garnet‐type (A 3 B 2 C O 12 ) near‐infrared (NIR) phosphors is a desirable research hotspot due to their prospective night vision, bioimaging, and plant growth utilizations. Meanwhile, the origin of multisite broad emission yet controversial topic. To resolve trouble, verifying accurately multiple occupancy sites key. Furthermore, it an urgent need for improving external quantum efficiency luminescent thermostability. Herein, in Y Sc Al (YSAO), advanced electron microscopy technique employed directly confirm that obtained broadband NIR originates from [ScO 6 ] octahedral [YO 8 dodecahedral sites. The optimal YSAO:5%Cr sample exhibits high (IQE/EQE = 74/31%) near‐zero thermal quenching (97%@423 K 92%@473 K). theoretical calculations experimental proofs reveal YSAO possesses structural rigidity wide bandgap, which responsible extremely thermostable luminescence. high‐power ‐converted LED device shows promising multifunctional applications. This work not only provides efficient phosphor with quenching, but also effective determination method emitting centers materials.

Language: Английский

---

Site-Selective Occupancy Control of Cr Ions toward Ultrabroad-Band Infrared Luminescence with a Spectral Width up to 419 nm

ACS Applied Materials & Interfaces, Journal Year: 2022, Volume and Issue: 14(47), P. 53101 - 53110

Published: Nov. 17, 2022

Infrared-emitting phosphor-converted light-emitting diodes (LEDs) are desirable light sources for a very wide range of applications such as spectroscopy analysis, nondestructive monitoring, covert information identification, and night-vision surveillance. The most important aspect infrared emitters is to cover the widest possible wavelength emitted light. However, developing ultrabroad-band based on converter technology still challenging task due lack suitable phosphor materials that emit in upon excitation from blue-emitting chips. Herein, this work demonstrates Cr3+-activated Mg2SiO4 phosphors with super spectral 600 1400 nm high internal quantum yield up 80.4% 460 excitation. Site-selective occupancy Cr3+ two different Mg sites lattice results distinct broad emission bands peaking at 760 970 nm, both which contribute luminescence full width half maximum (FWHM) 419 nm. This by far broadest best our knowledge. On basis, an LED prototype has been fabricated combination Mg2SiO4:Cr3+ blue chip, shows great potential imaging sensing applications. site-selective control Cr ions effective strategy Cr3+-doped phosphors.

Language: Английский

---

Producing Tunable Broadband Near-Infrared Emission through Co-Substitution in (Ga_1–xMg_x)(Ga_1–xGe_x)O₃:Cr³⁺

ACS Applied Materials & Interfaces, Journal Year: 2022, Volume and Issue: 14(45), P. 51157 - 51164

Published: Nov. 7, 2022

Broadband near-infrared (NIR) phosphors are in high demand for creating "smart" NIR phosphor-converted light-emitting diode (pc-LED) sources. In this work, a series of Cr3+-substituted NIR-emitting materials with highly efficient, broad, tunable emission spectra achieved by modifying the simple oxide Ga2O3 using [Mg2+-Ge4+] and [Ga3+-Ga3+] co-unit substitution. The results show that peak can be shifted from 726 to 830 nm while maintaining constant excitation blue light region, enabling extensive application. optical properties stem changes Cr3+ crystal field environment upon Intriguingly, temperature-dependent photoluminescence position shows virtually no change co-substituted materials. This abnormal phenomenon is found comprehensive embodiment weakening (red-shift) as temperature increases reduced local structure distortion (blue-shift) increasing temperature. quantum yield, emission, net-zero shift function make phosphor class optimal device incorporation. As result, their performance was studied coating on 450 emitting LED chip. fabricated demonstrates an excellent output power photoelectric conversion efficiency. study provides tunable, broadband spectroscopy applications contributes basic foundation Cr3+-activated phosphors.

Language: Английский

---

Simultaneous Absorption and Near‐Infrared Emission Enhancement of Cr³⁺ Ions in MgGa₂O₄ Spinel Oxide via Anionic F‐Substitution

Advanced Optical Materials, Journal Year: 2022, Volume and Issue: 11(5)

Published: Dec. 19, 2022

Abstract Near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are newly emerging broadband NIR light sources. However, the lack of high‐performance NIR‐emitting materials limits their popularization. Herein, an anionic F‐substitution strategy is presented to regulate absorption and emission MgGa 2 O 4 :Cr 3+ phosphors. Accordingly, enhancement as well redshift broadening achieved for F‐substituted (MGOF:Cr ) phosphors, simultaneously with high efficiency excellent thermal stability. Upon blue excitation, MGOF:0.02Cr phosphor exhibits a (650–1200 nm) peak wavelength (λ max 835 nm full width at half maximum ≈250 nm. Furthermore, has near‐unity internal quantum its intensity 150 °C maintains 94% initial value. A record external 60.6% further MGOF:0.08Cr redshifted λ 870 The Cr local structural alteration revealed account outstanding luminescence characteristics MGOF:Cr in view systematic characterization spectroscopic analysis. pc‐LED device good optical performance fabricated application semiconductor wafer inspection demonstrated. This study initiates new way design

Language: Английский

---

Thermal Stability Improvement of Cr³⁺‐Activated Broadband Near‐Infrared Phosphors via State Population Optimization

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(14)

Published: April 25, 2023

Abstract Technological progress has accelerated the researches into broadband near‐infrared (NIR) luminescent materials as next‐generation intelligent NIR light sources; however, poor thermal stability restricts applications of phosphors. Herein, new insights Cr 3+ ‐activated phosphors with improved are provided. The photoluminescence intensity originating from 4T2→4A2 emission CaLu 2 Al 4 SiO 12 :Cr (CLAS:Cr) optimal electron occupation ( T / E) increases up to 118% at 475 K compared that room temperature, which is best for phosphor. Accordingly, ideas design thermally stable proposed by optimizing population between and E states migration state. Finally, multifunctional CLAS:Cr in fluorescence ratio thermometry, X‐ray detection, phosphor‐converted light‐emitting diodes, bio‐imaging demonstrated.

Language: Английский

---

Long-Wavelength Near-Infrared Divalent Nickel-Activated Double-Perovskite Ba₂MgWO₆ Phosphor as Imaging for Human Fingers

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(33), P. 39472 - 39479

Published: Aug. 8, 2023

Transmission near-infrared (NIR) imaging technology has great potential for biomedical because of its lower water absorption coefficient and highly reduced photon scattering effect in biological tissues compared to visible light. The extent tissue is inversely proportional wavelength; therefore, principle, with long-wavelength NIR helps improve the resolution optical image, but deep high-resolution luminescence still very challenging technically. Here, we report discovery a Ba2MgWO6:Ni2+ double perovskite phosphor that emits broadband (1200-2000 nm) under 365 nm near-ultraviolet (UV) excitation, full width at half-maximum 255 nm. quantum efficiency optimized composition reached 16.67%. analysis crystal structure suggests Ni2+ ions preferentially occupy W6+ site octahedrons weak field, which leads large Stokes shift. An as-prepared pc-LED device was built by packaging an low-power near-UV-LED chip, tested generate clear venous vessels human fingers. These unique properties makes it promising application field sources body tissue..

Language: Английский

---

Continuous Ultra‐Broadband Near‐Infrared Sc₂O₃‐Based Nanophosphor Realized by Spectral Bridge of Cr³⁺‐Yb³⁺‐Cr⁴⁺ for Multiple Optical Applications

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(19)

Published: June 20, 2023

Abstract Cr 3+ ‐activated near‐infrared (NIR) phosphors are one of the most influential candidates for new generation intelligent NIR phosphor‐converted light‐emitting diode (pc‐LED) light sources. For spectral analysis, broader spectrum, more useful information it contains. Herein, ultra‐broadband Cr‐activated Sc 2 O 3 nanophosphors, which exhibit from 650 to 1600 nm, developed by sol–gel method. This emission originates presence and 4+ , two luminescent centers confirmed diffuse reflection spectra, electron paramagnetic resonance, time‐resolved photoluminescence temperature‐dependent spectra. The nanophosphor exhibits excellent temperature‐sensing performance with S A = 4.102% K −1 R 1.855% . Co‐doping Yb into nanophosphors builds ‐Yb ‐Cr model bridge gap located at 1000 forming a continuous spectrum ranging nm first time. Moreover, introduction improves thermal stability 29.49% 50.65% 150 °C. transmission spectra water, ethanol, peanut oil demonstrate that :Cr favor potential applications in analysis. construction realizing based on cheap blue LEDs provides novel effective insights.

Language: Английский

---