LED Components – Principles of Radiation Generation and Packaging

Winkler, Holger; Trinh, Quang Vinh; Khanh, Tran Quoc; Benker, Andreas; Bois, Charlotte; Petry, Ralf; Zych, Aleksander

doi:10.1002/9783527670147.ch3

Cited by 8 publications

(6 citation statements)

References 64 publications

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“…Especially for the former (blue) excitation it might offer filling the gap located ∼500 nm between emission of the chip (∼450-460 nm) and the (usually YAG:Ce) phosphor whose peak luminescence is around 550 nm. 47 At present one of the methods to deal with that problem is using LuAG:Ce, 47 but its emission is much less blue shifted than in the case of reported here ceramic SrS:Ce sintered the 1600 • C. This obviously would require more experiments, for example at higher temperatures (∼100-150 • C-the typical working temperature of LED phosphors) to find if this ceramics do not suffer from a thermal quenching. Nevertheless, these data evidence that altering processing of a known phosphor may lead to a greatly modified luminescent characteristics.…”

Section: Resultsmentioning

confidence: 80%

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities

Zych¹,

Kulesza²,

Zeler³

et al. 2015

ECS J. Solid State Sci. Technol.

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Properties of SrS:Ce and LuPO 4 :Eu sintered ceramics are reported for the first time. Both materials were sintered at various temperatures up to 1700 • C. SrS:Ce sintered ceramics were found to form a new luminescent center(s) giving emission with maximum around 620 nm or 700 nm for 0.05% Ce and 5% Ce, respectively. This red-infrared band was continuously more potent with increasing sintering temperature and also for higher Ce concentrations both in photo-and radioluminescence. The new luminescent feature was shown to be formed by Ce 3+ ions with strongly perturbed symmetry compared to the octahedral one offered by the SrS host. After irradiation with X-rays LuPO 4 :Eu sintered ceramics produced a long lasting afterglow luminescence which was connected with thermoluminescence around 200 • C. The shape of the glow curve bands change with Eu concentration. For Eu content of 0.1% the TL band was quite symmetrical. For 5% of Eu the TL glow band appeared more structured and the 200 • C peak was associated with intense components around 150 • C and 330 • C. The former contributed into more potent afterglow at room temperature. Sintering of SrS:Ce and LuPO 4 :Eu induced new luminescent characteristics of both compositions endowing them with new, potentially usable functionalities.

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Section: Resultsmentioning

confidence: 80%

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities

Zych¹,

Kulesza²,

Zeler³

et al. 2015

ECS J. Solid State Sci. Technol.

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“…Photoluminescence properties of Eu 2+ are well known as they have been thoroughly investigated, also for practical applications. There is a vast number of materials in which the 4f 6 5d 1 →4f 7 radiative relaxation of Eu 2+ was reported both in photoluminescence and in scintillation [24][25][26][27]. The very important, widely applied storage phosphors, BaF-Br:Eu and CsBr:Eu, are also activated with Eu 2+ ions [28][29][30][31][32][33][34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Fine structure in high resolution 4f7–4f65d excitation and emission spectra of X-ray induced Eu2+ centers in LuPO4:Eu sintered ceramics

Zeler

Meijerink

Kulesza

et al. 2019

Journal of Luminescence

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“…Improvements to light source design can be critical to optimizing the photodynamic reactions that determine the success of PDT (10,11). One of the main features of LED technology is that it can be used to create light sources (lamps) with very well‐defined photometric emission characteristics that can operate at a single output spectrum or at several spectra through the combination of different sources or the use of photon‐conversion filters like phosphorus coatings (12,13). This flexibility permits the creation of PDT devices that can be used to treat a range of disorders, such as onychomycosis, acne and rosacea, superficial and nodular basal cell carcinoma, Paget disease and nail psoriasis (4).…”

Section: Discussionmentioning

confidence: 99%

Effect of Nail Thickness on Visible Radiation Transmittance: Implications for New Photodynamic Therapy Technologies in Onychomycosis

Gálvez¹,

Aguilera

Gálvez

et al. 2020

Photochem & Photobiology

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Photodynamic therapy is taking importance as a nonintrusive treatment for nail onychomycosis. Knowledge of true transmittance values across nails could lead to qualitative and quantitative improvements in light‐based treatments. We have characterized the spectral transmittance of healthy and fungally infected human fingernails and toenails according to nail thickness, and we propose a surface transmittance model for the small‐scale optimization of light‐based treatments. Transmittance of fingernails and toenails was analyzed by means of spectroradiometric measurements under solar‐simulated visible light radiation (400 nm to 750 nm). The nail thickness was measured by means of microscope measurement. Transmittance was highest at longer wavelengths and decreased gradually as the wavelengths became shorter but with a significant nail transmittance of around 20% in the blue region of the spectrum. In the case of nails affected by onychomycosis, transmittance fell to under 10% because of the thickness of the nails, with no changes in spectral characteristics of transmitted light. Nail thickness is the main variable controlling exponentially light transmission in the visible spectrum and not only red radiation is effective for nail onychomycosis PDT. Blue light, the spectral band more effective for PPIX absorption is also effectively transmitted.

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LED Components – Principles of Radiation Generation and Packaging

Cited by 8 publications

References 64 publications

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities

Fine structure in high resolution 4f7–4f65d excitation and emission spectra of X-ray induced Eu2+ centers in LuPO4:Eu sintered ceramics

Effect of Nail Thickness on Visible Radiation Transmittance: Implications for New Photodynamic Therapy Technologies in Onychomycosis

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LED Components – Principles of Radiation Generation and Packaging

Cited by 8 publications

References 64 publications

SrS:Ce and LuPO4:Eu Sintered Ceramics: Old Phosphors with New Functionalities

SrS:Ce and LuPO4:Eu Sintered Ceramics: Old Phosphors with New Functionalities

Fine structure in high resolution 4f7–4f65d excitation and emission spectra of X-ray induced Eu2+ centers in LuPO4:Eu sintered ceramics

Effect of Nail Thickness on Visible Radiation Transmittance: Implications for New Photodynamic Therapy Technologies in Onychomycosis

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Product

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About

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities

SrS:Ce and LuPO₄:Eu Sintered Ceramics: Old Phosphors with New Functionalities