Color deviations in phosphor converted high power light emitting diodes under different dimming schemes

Bogna Ludwiczak; Wolfgang Jantsch

doi:10.1016/j.jlumin.2014.10.037

Color deviations in phosphor converted high power light emitting diodes under different dimming schemes

Bogna Ludwiczak, Wolfgang Jantsch

Department of Solid State Physics

Research output: Contribution to journal › Article › peer-review

Abstract

We investigate experimentally the color stability of high power phosphor converted InGaN LEDs under pulse width modulation (PWM) and continuous current reduction (CCR) dimming modes and for varied operation temperatures. Our measurements reveal that the chromaticity coordinate pathways of the warm white and the cold white LED׳s differ for the same operation conditions. The color deviation- minimizing phenomenon of opposite peak wavelength shifts appears only for a cold white LED under CCR driving mode. This favorable effect does not occur for warm white LEDs. This type of LED exhibits the best color stability under PWM driving mode. The experimental results are consistently explained in terms of the quantum confined Stark effect and temperature induced changes of the LED emission.

Original language	English
Pages (from-to)	384-389
Number of pages	6
Journal	Journal of Luminescence
Volume	158
DOIs	https://doi.org/10.1016/j.jlumin.2014.10.037
Publication status	Published - Feb 2015

Fields of science

210006 Nanotechnology
103 Physics, Astronomy
103011 Semiconductor physics
103018 Materials physics
202032 Photovoltaics
103009 Solid state physics
103017 Magnetism

JKU Focus areas

Engineering and Natural Sciences (in general)

Access to Document

10.1016/j.jlumin.2014.10.037

Cite this

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title = "Color deviations in phosphor converted high power light emitting diodes under different dimming schemes",

abstract = "We investigate experimentally the color stability of high power phosphor converted InGaN LEDs under pulse width modulation (PWM) and continuous current reduction (CCR) dimming modes and for varied operation temperatures. Our measurements reveal that the chromaticity coordinate pathways of the warm white and the cold white LED׳s differ for the same operation conditions. The color deviation- minimizing phenomenon of opposite peak wavelength shifts appears only for a cold white LED under CCR driving mode. This favorable effect does not occur for warm white LEDs. This type of LED exhibits the best color stability under PWM driving mode. The experimental results are consistently explained in terms of the quantum confined Stark effect and temperature induced changes of the LED emission.",

author = "Bogna Ludwiczak and Wolfgang Jantsch",

year = "2015",

month = feb,

doi = "10.1016/j.jlumin.2014.10.037",

language = "English",

volume = "158",

pages = "384--389",

journal = "Journal of Luminescence",

publisher = "Elsevier",

}

TY - JOUR

T1 - Color deviations in phosphor converted high power light emitting diodes under different dimming schemes

AU - Ludwiczak, Bogna

AU - Jantsch, Wolfgang

PY - 2015/2

Y1 - 2015/2

N2 - We investigate experimentally the color stability of high power phosphor converted InGaN LEDs under pulse width modulation (PWM) and continuous current reduction (CCR) dimming modes and for varied operation temperatures. Our measurements reveal that the chromaticity coordinate pathways of the warm white and the cold white LED׳s differ for the same operation conditions. The color deviation- minimizing phenomenon of opposite peak wavelength shifts appears only for a cold white LED under CCR driving mode. This favorable effect does not occur for warm white LEDs. This type of LED exhibits the best color stability under PWM driving mode. The experimental results are consistently explained in terms of the quantum confined Stark effect and temperature induced changes of the LED emission.

AB - We investigate experimentally the color stability of high power phosphor converted InGaN LEDs under pulse width modulation (PWM) and continuous current reduction (CCR) dimming modes and for varied operation temperatures. Our measurements reveal that the chromaticity coordinate pathways of the warm white and the cold white LED׳s differ for the same operation conditions. The color deviation- minimizing phenomenon of opposite peak wavelength shifts appears only for a cold white LED under CCR driving mode. This favorable effect does not occur for warm white LEDs. This type of LED exhibits the best color stability under PWM driving mode. The experimental results are consistently explained in terms of the quantum confined Stark effect and temperature induced changes of the LED emission.

U2 - 10.1016/j.jlumin.2014.10.037

DO - 10.1016/j.jlumin.2014.10.037

M3 - Article

VL - 158

SP - 384

EP - 389

JO - Journal of Luminescence

JF - Journal of Luminescence

ER -