Monolithically Integrating III‐Nitride Quantum Structure for Full‐Spectrum White LED via Bandgap Engineering Heteroepitaxial Growth

Laser & Photonics Review, Journal Year: 2023, Volume and Issue: 17(3)

Published: Jan. 1, 2023

Abstract Great progress made by heteroepitaxial growth technology encourages rapid development of III‐nitride structures and their applications in extensive fields. Particularly, innate bandgap tunability materials renders them attractive for white light‐emitting diodes (WLEDs) that are considered as next‐generation solid‐state lighting sources. However, commercial phosphor‐converted WLEDs suffer from poor color rendering index (CRI) intense blue component, hard to fulfill demanding requirements simultaneously energy efficiency healthy lighting. Here, an efficient full‐spectrum WLED excited monolithically integrated quantum structure is reported, which trichromatic InGaN/GaN multiple wells constructed engineering heteroepitaxy allowing flexible regulation indium composition barrier thickness manipulate carrier transport behavior. Furthermore, relationship between structural parameters emission characteristics well impact on light performance systematically demonstrated. Combined with commonly used green‐red phosphor mixture, the fabricated warm/cold can emit broadband continuous spectra low‐ratio first exhibiting superior CRI (> 97/98), fidelity (97/97), saturation (100/99), luminous efficacy (>120/140 lm W −1 ). This work demonstrates advantages bandgap‐engineered applied excitation source, opens up new avenues exploration high‐quality

Language: Английский

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Tunable light emission of Bi and V-doped borosilicate glasses for application in white light-emitting diodes

Ceramics International, Journal Year: 2024, Volume and Issue: 50(7), P. 11893 - 11903

Published: Jan. 9, 2024

Melt-quenched borosilicate glasses, co-doped with Bi and V ions, exhibited broad visible spectrum emissions. ions primarily existed as Bi3+, acting network modifiers, lowering the glass transition temperature linearly increasing content. V5+ adopted tetrahedral coordination [VO4]3- units. Photoluminescence of is shifted from blue to longer wavelengths higher content, associated stabilization Bi2+ presence Bi3+ in different local environments. Combined glasses emitted light covering entire spectrum, offering potential for white LED applications correlated color temperatures ranging 6135 4010 K. The highest QY was 11.9 8.0 % upon excitation at 325 340 nm.

Language: Английский

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Towards opto-structural parameters to enhance the circularly polarized luminescence brightness of Eu^III β-diketone complexes with chiral auxiliary ligands

Journal of Materials Chemistry C, Journal Year: 2024, Volume and Issue: 12(14), P. 5097 - 5107

Published: Jan. 1, 2024

Tuning the overall emission quantum yield ( ϕ LLn), dissymmetry factor g lum ), as well CPL brightness by changing electronic structure and microsymmetry of Eu III coordination polyhedron.

Language: Английский

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Luminescence Properties and Mechanisms of Ca10(PO4)6F2:Er3+ as a Green Phosphor for White LEDs

Journal of Solid State Chemistry, Journal Year: 2025, Volume and Issue: unknown, P. 125281 - 125281

Published: Feb. 1, 2025

Language: Английский

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Role of Vibronic Coupling for the Dynamics of Intersystem Crossing in Eu³⁺ Complexes: an Avenue for Brighter Compounds

Journal of Chemical Theory and Computation, Journal Year: 2025, Volume and Issue: unknown

Published: March 7, 2025

Understanding the dynamics of photophysical processes in Ln3+ complexes remains challenging due to intricate nature involving metallic center, where sensitization (antenna effect) plays a pivotal role. Current studies have often overlooked vibronic coupling within antenna effect, leading incomplete insights into excited-state dynamics. To address these shortcomings, we introduce novel theoretical and computational approach that leverages impact vibrational modes S1 T1 states this effect through correlation function formalism, offering comprehensive view intersystem crossing (ISC). Our achieves desirable alignment between empirical rates, outperforming previously employed semiclassical methods. A groundbreaking finding is with vibrations 700-1600 cm-1 energy range crucial for higher ISC, local mode analysis identified process driven by delocalized across molecule. These results shed light on key molecular fragments responsible coupling, opening an avenue harnessing faster ISC tailoring ligand scaffold. Overall, it also demonstrates how can serve as bridge theory experiment, furnishing detailed mechanistic roadmap development brighter compounds.

Language: Английский

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Flexible Large Area SWIR Colloidal Quantum Dot Down Converters Based on Scalable Manufacturing Processes

Advanced Materials Technologies, Journal Year: 2025, Volume and Issue: unknown

Published: March 6, 2025

Abstract The growing demand for efficient, compact, and cost‐effective short‐wave infrared (SWIR) emitters has surged due to their wide‐ranging applications in industries such as biomedical diagnostics, food pharmaceutical quality control, agriculture, environmental monitoring. Conventional SWIR sources are limited by bulkiness, inefficiency, high cost, while phosphor‐converted Light Emitting Diodes (pc‐LEDs) based on transition metal ions or lanthanides face challenges fixed wavelengths, narrow absorption bands, high‐temperature manufacturing processes. Lead sulfide (PbS) colloidal quantum dots (CQDs) offer a promising alternative, combining wavelength tunability, synthesis simplicity, cost‐effectiveness, photoluminescence yield (PLQY). In this study, scalable process is introduced fabricate flexible, high‐performance down‐converters (DCs) PbS CQDs embedded an ethyl cellulose (EC) polymer matrix. Performance enhancements achieved through solution‐phase ligand exchange (SPLE) with 1‐dodecanethiol (DDthiol), improving passivation device efficiency. When excited 980 nm LED, the DC achieves output power density of 0.54 mW mm − 2 photon conversion efficiency ≈15%. A practical application demonstrated custom‐built torch thin‐film CQD DCs, shown penetrate smoke, highlighting potential technology real‐world use cases.

Language: Английский

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Lanthanide-doped luminescent perovskites: A review of synthesis, properties, and applications

Journal of Luminescence, Journal Year: 2022, Volume and Issue: 252, P. 119406 - 119406

Published: Oct. 13, 2022

Language: Английский

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All-Inorganic Green Synthesis of Small-Sized and Efficient K₂SiF₆:Mn⁴⁺ Phosphor for Mini-LED Displays

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(46), P. 53738 - 53745

Published: Nov. 10, 2023

High-resolution liquid crystal display (LCD) backlight requires a color conversion layer featuring micrometer light-emitting particles and uniform morphology. The widely used commercial red-emitting K2SiF6:Mn4+ phosphor, showing promise as light-conversion candidate, faces limitations due to its toxic synthesis process, large particle size, poor moisture resistance. We successfully demonstrated an efficient substitution of the highly HF/TEOS/KHF2 solvent system with commonly HCl/SiO2/KF synthesize small-sized phosphor. Additionally, surface passivation was performed enhance luminescence intensity resistance moisture, denoted K2SiF6:Mn4+@CaF2. Accordingly, K2SiF6:Mn4+@CaF2 phosphor presents high efficiency (99.87%/32.84% IQE/EQE) average size ∼2.67 μm. Notably, after exposure 85% humidity 85 °C temperature for 3 h, remains at 47.4% K2SiF6:Mn4+@CaF2, while 21.2% pristine K2SiF6:Mn4+, only 3.5% synthesized by TEOS. These advancements hold great potential improving high-resolution LCD backlighting, particularly displays micron-level pixels, opening up new possibilities enhanced technology.

Language: Английский

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Double perovskite structured Ca2MgWO6:Sm3+ nanophosphor: Tailored for future-generation WLEDs and dosimetry applications

Journal of Alloys and Compounds, Journal Year: 2023, Volume and Issue: 960, P. 170662 - 170662

Published: May 23, 2023

Language: Английский

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Efficient and bright broadband electroluminescence based on environment-friendly metal halide nanoclusters

Light Science & Applications, Journal Year: 2024, Volume and Issue: 13(1)

Published: April 7, 2024

Abstract Broadband electroluminescence based on environment-friendly emitters is promising for healthy lighting yet remains an unprecedented challenge to progress. The copper halide-based are competitive candidates broadband emission, but their high-performance shows inadequate broad emission bandwidth of less than 90 nm. Here, we demonstrate efficient ultra-broadband from a halide (CuI) nanocluster single emitter prepared by one-step solution synthesis-deposition process, through dedicated design ligands and subtle selection solvents. CuI exhibits high rigidity in the excitation state as well dual-emissive modes phosphorescence temperature-activated delayed fluorescence, enabling uniform cluster-composed film show excellent stability photoluminescent efficiency. In consequence, light-emitting diodes (LEDs) present nearly identical performance inert or air atmosphere without encapsulation outstanding high-temperature operation performance, reaching full width at half maximum (FWHM) ~120 nm, peak external quantum efficiency 13%, record luminance ~50,000 cd m −2 , operating half-lifetime 137 h 100 . results highlight potential nanoclusters next-generation lighting.

Language: Английский

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