Degradation of AlGaN-based ultraviolet light emitting diodes

Sawyer, Shayla; Rumyantsev, Sergey; Shur, M. S.

doi:10.1016/j.sse.2008.01.027

Cited by 45 publications

(29 citation statements)

References 8 publications

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“…Gradual degradation reported in Refs. [382][383][384] was not related to increased nonradiative recombination in the MQW region, but rather ascribed to generation of defects in the AlGaN cladding layers. The effect was variously explained by migration of Al in the p-AlGaN cladding layer or to enhanced compensation of p-type conductivity in this layer.…”

Section: V2leds Degradation Studiesmentioning

confidence: 96%

Deep traps in GaN-based structures as affecting the performance of GaN devices

Polyakov

Lee

2015

Materials Science and Engineering: R: Reports

207

177

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Section: V2leds Degradation Studiesmentioning

confidence: 96%

Deep traps in GaN-based structures as affecting the performance of GaN devices

Polyakov

Lee

2015

Materials Science and Engineering: R: Reports

207

177

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“…4). Such behaviour is quite common for GaN-based optoelectronic devices during ageing tests [3,9]. While these changes are small (a number of additional non-radiative recombination centres is not high enough), they practically do not affect the light output characteristic.…”

Section: Noise Characteristics During the Ageing Experimentsmentioning

confidence: 97%

“…The essential feature of low-frequency noise spectroscopy is that measurements are performed under normal bias conditions near the equilibrium state and are nondestructive [6,7]. Due to this reason, the lowfrequency noise characteristics of GaN-based LEDs are of high interest to scientific community [8][9][10][11][12]. However, there are practically no published investigations on the low-frequency noise characteristics of white LEDs during a long ageing experiment at room temperature and manufacturer permissible forward current.…”

Section: Introductionmentioning

confidence: 99%

Low-frequency noise characteristics of high-power white LED during long-term aging experiment

Glemža¹,

Matukas²,

Pralgauskaitė³

et al. 2018

physics

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Low-frequency electrical and optical noise characteristics of a high power white InGaN LED and the cross-correlation coefficient between these fluctuations are investigated during the long-term ageing experiment (28000 h). The analysis of cross-correlation shows that the correlated part of the low-frequency electrical noise, which indicates physical processes in the active area of the LED, varies during the ageing experiment. Two main stages are distinguished considering the rapid changes of the noise characteristics. The initial stage (after the first 1100 h) is followed by the decrease in the noise power at low forward currents and the increase in the light output. The final stage (after 28000 h) is characterized by a strong growth of the low-frequency noise, the decrease of the light output and the increase of the correlated part of electrical and optical fluctuations. These changes mean a failure in the active layer of the LED. The optical output decomposition into two spectral parts, the radiation generated by the LED chip and the radiation generated by the phosphor layer, enables evaluation of the phosphor layer influence on the degradation process of device optical characteristics. Despite the fact that this layer contributes to the variation of the LED chromatic properties, the cross-correlation analysis has shown that the phosphor layer does not act as a possible noise source during the ageing experiment.

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“…So far, aging of LEDs with emission wavelength as short as 280 nm has been studied by measuring electrical, far field optical, and noise properties. 2,3,[5][6][7] Aging mechanisms, such current crowding around contacts, 2 at macroscopic defects, 3 generation of defects 5 and change in alloy composition in the p-side cladding layer 7 have been proposed. Recently, we have explored a device emitting at 285 nm using scanning near field optical microscopy ͑SNOM͒ and revealed a yet another aging mechanism related to domainlike AlGaN compositional inhomogeneities in the QWs.…”

Section: Optical Studies Of Degradation Of Algan Quantum Well Based Dmentioning

confidence: 99%