Excitation dependent quenching of luminescence in LED phosphors

Shchekin, O.B.; Schmidt, Peter J.; Jin, Fahong; Lawrence, Nate; Vampola, Kenneth J.; Bechtel, Helmut; Chamberlin, D. R.; Mueller‐Mach, Regina; Mueller, Gerd

doi:10.1002/pssr.201600006

Cited by 29 publications

(35 citation statements)

References 15 publications

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“…The Cerium‐doped aluminum garnets show little dependence of photo‐quenching on temperature, but, depending on composition, may exhibit considerable thermal quenching. Our further investigations into the nature of the quenching process in (Ba,Sr) 2 Si 5 N 8 :Eu showed that the decrease in efficiency is closely predicted by quadratic dependence on the concentration of excited europium activators. This observation suggests that the excited state absorption is the likely culprit behind PTQ in these materials.…”

Section: Enabling Technologies For High‐luminance Ledsmentioning

confidence: 71%

Progress in high-luminance LED technology for solid-state lighting

Bhardwaj

Cesaratto

Wildeson

et al. 2017

Phys. Status Solidi A

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Increasing the luminance of white LEDs to the 200 Mnit level and beyond, opens a completely new design space for a wide range of lighting applications, by allowing significant reductions in optics and luminaire size as well as costs. Moreover, new applications, such as dynamic beam steering, are enabled by the ability to create arrays of densely packed, individually addressable high‐luminance emitters. The development of such high‐luminance LEDs requires improvements in all LED technology elements. In this paper, we discuss recent advances in epitaxy, die, phosphor, and package technology that are critical to achieving these benefits.

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Section: Enabling Technologies For High‐luminance Ledsmentioning

confidence: 71%

Progress in high-luminance LED technology for solid-state lighting

Bhardwaj

Cesaratto

Wildeson

et al. 2017

Phys. Status Solidi A

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“…To verify the number of maximum acceptable photons (N MAP ) for each phosphor, a In addition, to clearly distinguish the effects of self-heating of non-radiative recombination, the YAG was measured in CW mode and pulsed mode, respectively. 22,25 Light source irradiated in pulsed mode was excited with a frequency of 3.57 Hz to prevent photons from accumulating due to long decay time and thereby self-heating, as shown in Fig. 3.…”

Section: Methodsmentioning

confidence: 99%

Luminescence Saturation in Inorganic Phosphors under High Flux of Photon Excitation

Ahn¹,

Park²,

Lim³

et al. 2018

ECS J. Solid State Sci. Technol.

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The luminescence behavior of certain phosphor material shows non-linearity within a specific photon excitation range, depending upon the activator and/or the host lattice. Conventionally, the absorption and emission characteristics of phosphors are measured using a spectrometer with a light source such as a xenon lamp. Herein, a new measurement system was set up to investigate luminescence saturation in inorganic phosphors. The effect of the environment on the longevity of the material has been examined for each attribute and the conditions for luminescence saturation have been discussed. © The Author(s) 2018. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. Phosphor-converted white light-emitting diodes (pc-WLEDs) are widely used as a light source in liquid crystal displays and in solidstate lighting. They are known to be more stable than Ne-, fluorescent-, and halogen-lamps. In addition, they exhibit an excellent efficiency of ∼246 lm/W at 20 mA. The pc-WLEDs directly convert electrical energy into light. [1][2][3][4] In this conversion process, some electrical energy is dissipated in the form of heat, which leads to a decrease in the light efficiency. Heat sinks and cooling fans are also sources of LED power consumption that lead to a non-negligible decline in the lighting efficiency. 5,6 As the applications of high-power pc-WLEDs continue to increase, ensuring the reliability of these devices in terms of their optical characteristics and thermal stability has gained importance. In particular, a decrease in the efficiency of the power output and life-time has also been reported. 7,8 As the current density of the pc-WLEDs increases, their light output also increases and more heat is emitted. [9][10][11] It is known that the heat generated in the device increases the temperature of the active region of the quantum-well (QW) layer in the LED structure. The elevated temperature may also decrease the bandgap of the active region, which would cause the generation of more heat due to non-radiative recombination in the active region. This positive feedback process reduces the quantum efficiency of the LED and eventually causes degradation of its luminance and lifetime. 12 However, a more commonly encountered phenomenon is droop, in which the efficiency decreases over a certain level as the output increases. Although many studies have focused on clarifying the cause of the droop phenomenon and implicated sources such as carrier heating, carrier escape, and the Auger effect, the exact cause has not been identified as yet. [13][14][15][16] Therefore, further detailed studies are necessary. In general, the reliability of pc-WLE...

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“…Light-emitting diode (LED) lamps using phosphor conversion of 350–480 nm LED radiation have drawn much attention, and are notably expected to replace traditional illumination sources due to their superior features such as low power consumption, long lifetime, high efficiency, small volume, and low maintenance [1,2,3]. The InGaN-based white light-emitting diode (WLED) is a new kind of solid-state illumination technology, the efficiency of which has already surpassed that of traditional incandescent bulbs and fluorescent lamps [4,5,6,7,8,9,10,11]. WLEDs can be achieved by the incorporation of tricolor phosphors (blue, green, and red) with near-UV-InGaN chips or phosphors (green and red) with blue InGaN chips.…”

Section: Introductionmentioning

confidence: 99%

“…Phosphor materials play a very important role in WLEDs [4,5,6,7,8]. Although near-UV-InGaN chips can offer higher energy to pump the phosphors, they also present low photochemical stability under ultraviolet UV irradiation [9,10]. As a result, it is necessary to develop phosphors which may be excited by blue InGaN LED chips that have high levels of efficiency and small thermal quenching.…”

Section: Introductionmentioning

confidence: 99%

Green Phosphors Based on 9,10-bis((4-((3,7-dimethyloctyl)oxy) phenyl) ethynyl) Anthracene for LED

et al. 2019

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An anthracene aromatic unit was introduced into the phenylethynyl structure by a rigid acetylene linkage at the C-9 and C-10 positions via Sonogashira coupling reactions, resulting in a planar and straight-backbone molecule (9,10-bis((4-((3,7-dimethyloctyl)oxy) phenyl) ethynyl) anthracene) (BPEA). Thermogravimetric analysis demonstrated the good thermal stability of the BPEA. Photoluminescence analysis showed that a suitable expanded π-conjugation in the BPEA made its excitation band extend into the visible region, and an intense green emission was observed under blue-light excitation. A bright green light-emitting diode with an efficiency of 18.22 lm/w was fabricated by coating the organic phosphor onto a 460 nm-emitting InGaN chip. All the results indicate that BPEA is a useful green-emitting material which is efficiently excited by blue light, and therefore, that it could be applied in many fields without UV radiation.

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Excitation dependent quenching of luminescence in LED phosphors

Cited by 29 publications

References 15 publications

Progress in high-luminance LED technology for solid-state lighting

Progress in high-luminance LED technology for solid-state lighting

Luminescence Saturation in Inorganic Phosphors under High Flux of Photon Excitation

Green Phosphors Based on 9,10-bis((4-((3,7-dimethyloctyl)oxy) phenyl) ethynyl) Anthracene for LED

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