On spectral and thermal behaviors of AlGaInP light-emitting diodes under pulse-width modulation

Manninen, Pasi; Orreveteläinen, Pasi

doi:10.1063/1.2805198

Cited by 47 publications

(33 citation statements)

References 11 publications

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“…When designing high-power and large-area structures for dimming the LEDs operated in a pulse-width modulation mode, 16 these effects need to be fully understood, characterized, and taken into account. In particular, the p + -cladding layer could be nominally doped and the metal contact needs to cover the entire surface of the mesa.…”

Section: Discussionmentioning

confidence: 99%

The effect of current crowding on the heat and light pattern in high-power AlGaAs light emitting diodes

Zinovchuk

Malyutenko

et al. 2008

Journal of Applied Physics

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The results of the light and temperature micromapping in AlGaAs light emitting diodes grown by liquid phase epitaxy as double heterostructures and emitting at ϳ 0.87 m are presented. At a driving current well above the safe operating limit ͑Ͼ300 mA͒, the nonuniform light pattern and local self-heating ͑with temperature gradient of about 950°C / cm͒ followed by catastrophic degradation of a device were detected with the charge coupled device and infrared microscopes operating in a pulsed mode. These were shown to result from the current crowding effect in the active and contact areas of a device. Good agreement between the theory and experiment was found.

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Section: Discussionmentioning

confidence: 99%

The effect of current crowding on the heat and light pattern in high-power AlGaAs light emitting diodes

Zinovchuk

Malyutenko

et al. 2008

Journal of Applied Physics

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“…The wavelength shift is caused by the residual increase in temperature associated with the increase in dissipated power with increasing bias current [13,14].…”

Section: Spectral Distributionmentioning

confidence: 99%

Spectral Radiation Drift of LEDs Under Step-Mode Operation and Its Effect on the Measurement of the Non-Linearity of Radiation Thermometers

Wei

Yuan²,

Bloembergen³

et al. 2011

Int J Thermophys

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The non-linearity (NL) of radiation thermometers is critically involved when realizing ITS-90 above the silver point. It has to be corrected for, and its uncertainty should be adequately specified. In this article, results are presented of NL measurements based upon the superposition method and involving light emitting diodes (LEDs) with high radiance output, peaked at a wavelength of 645 nm. To this end, the two LEDs in question have been operated in the pulse mode with a fixed phase shift. Their spectral radiances have been measured by the radiation thermometers to be tested, separately or superimposed by means of a beam splitter. Still the drift in the spectral radiance observed after switching on the LEDs has to be taken into account and corrected for, since this drift, interfering during the superposition procedure, could corrupt the sum rule for the fluxes involved, which is the crux of the superposition method. Therefore, experimental research has been carried out to characterize the drift of LEDs operated in the pulse mode with a fixed phase shift. The result indicated that the drift could be roughly specified in terms of characteristic time intervals: non-linear drift in the first tens of seconds followed by a quasi-linear drift in the subsequent time interval. The crossover time from non-linear to quasi-linear drift could be ascertained by experiment. In the course of the superposition process, switching of the LEDs was done in such a way that only the quasi-linear part of the drift was involved which allowed for the correction of the drift in the NL measurements, as will be reported. Two radiation thermometers were involved in the NL measurements at radiance temperatures between the silver point and 3153 K: an LP-4, with a central wavelength 123 2588 Int J Thermophys (2011) 32:2587-2599 of 650 nm and 10 nm bandwidth, manufactured by KE-Technologie and the primary standard pyrometer PSP, with a central wavelength of 660 nm and 10 nm bandwidth, developed by NIM.

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“…Under current injection, only a portion of the electrical power is converted into optical power while the rest is dissipated in the form of heat accumulating in the p-n junction before propagating to the entire LED chip [16][17][18][19][20]. As the junction temperature rises during operation, the optical properties of the LED electroluminescence result in red-shifting of the peak wavelength, decreasing optical intensity, and broadening spectrum [17,21].…”

Section: Introductionmentioning

confidence: 98%

Color gamut variation of LED-lit LCD at different module temperatures

Chiu¹,

Lee²

2010

Optics Communications

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On spectral and thermal behaviors of AlGaInP light-emitting diodes under pulse-width modulation

Abstract: P5Publication 5 P. Manninen and P. Orreveteläinen, "On spectral and thermal behaviors of AlGaInP light-emitting diodes under pulse-width modulation," Appl.

Cited by 47 publications

References 11 publications

The effect of current crowding on the heat and light pattern in high-power AlGaAs light emitting diodes

The effect of current crowding on the heat and light pattern in high-power AlGaAs light emitting diodes

Spectral Radiation Drift of LEDs Under Step-Mode Operation and Its Effect on the Measurement of the Non-Linearity of Radiation Thermometers

Color gamut variation of LED-lit LCD at different module temperatures

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