Temperature and thermal characteristics of InGaN/GaN vertical light-emitting diodes on electroplated copper

Lee, D H; Lee, H K; Yu, Jae Su; Bae, Seong-Ju; Choi, Jungwook; Kim, D H; Ju, Inchan; Song, Kyung; Kim, J M; Shin, Chan-Soo

doi:10.1088/0268-1242/26/5/055014

Cited by 20 publications

(14 citation statements)

References 27 publications

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“…The lower voltage of LED 3 may be attributed to the better heat dissipation and substrate conductivity of the nanowire LED on the Cu substrate, which is consistent with other reports. 21,48,49 As shown in the inset of Figure 6a, the optical image of light emission from the LED device on the Cu substrate demonstrates the successful fabrication of such a nanowire on metal substrates. Figure 6b shows the relative light output power of both LED 1 and LED 3 for comparison.…”

Section: Results and Discussionmentioning

confidence: 92%

“…Generally, quantum efficiencies, output power, and lifetime reduce rapidly when the junction temperature increases. 21 Therefore, managing heat dissipation is seriously considered. Besides the applications in solid-state lighting illumination, the use of LEDs in telecommunications and decoration displays for the flexible electronics devices has also been intensively developed owing to the feasible integration of such LEDs in these electronic devices.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication of Phosphor-Free III-Nitride Nanowire Light-Emitting Diodes on Metal Substrates for Flexible Photonics

Philip¹,

Choudhary²,

Djavid³

et al. 2017

ACS Omega

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In this paper, we report our study on high-performance III-nitride nanowire light-emitting diodes (LEDs) on copper (Cu) substrates via the substrate-transfer process. Nanowire LED structures were first grown on silicon-on-insulator (SOI) substrates by molecular beam epitaxy. Subsequently, the SOI substrate was removed by combining dry- and wet-etching processes. Compared to conventional nanowire LEDs on Si, the nanowire LEDs on Cu exhibit several advantages, including more efficient thermal management and enhanced light-extraction efficiency (LEE) because of the usage of metal reflectors and highly thermally conductive metal substrates. The LED on Cu, therefore, has stronger photoluminescence, electroluminescence intensities, and better current–voltage characteristics compared to the conventional nanowire LED on Si. Our simulation results further confirm the improved device performance of LEDs on Cu, compared to LEDs on Si. The LEE of the nanowire LED on Cu is nine times higher than that of the LED on Si at the same nanowire radius of 60 nm and spacing of 130 nm. Moreover, by engineering the device-active region, we achieved high-brightness phosphor-free LEDs on Cu with highly stable white-light emission and high color-rendering index of ∼95, showing their promising applications in general lighting, flexible displays, and wearable applications.

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Section: Results and Discussionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Fabrication of Phosphor-Free III-Nitride Nanowire Light-Emitting Diodes on Metal Substrates for Flexible Photonics

Philip¹,

Choudhary²,

Djavid³

et al. 2017

ACS Omega

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show abstract

“…It is important to have adequate thermal management to remove this waste heat by either conduction or convection, as excessive increases in temperature at the LED junction directly affect LED-performance. In a short-term this could result in color shifts and reduced light output (intensity), while in the long-term accelerated lumen depreciation may take place (Park et al, 2005; Lee et al, 2011; Huang et al, 2015; Han et al, 2015; Dalapati et al, 2016). While the so-called “T-droop”, i.e.…”

Section: Resultsmentioning

confidence: 99%

Optogenetic manipulation of individual or whole populationCaenorhabditis elegansworms with an under hundred-dollar tool: the OptoArm

Koopman

Janssen

Nollen

2021

Preprint

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Optogenetic tools have revolutionized the study of neuronal circuits in Caenorhabditis elegans. The expression of light-sensitive ion channels or pumps under specific promotors allows researchers to modify the behavior of excitable cells. Several optogenetic systems have been developed to spatially and temporally photoactivate light-sensitive actuators in C. elegans. Nevertheless, their high costs and low flexibility have limited wide access to optogenetics. Here, we developed an inexpensive, easy-to-build, and adjustable optogenetics device for use on different microscopes and worm trackers, called the OptoArm. The OptoArm allows for single- and multiple-worm illumination and is adaptable in terms of light intensity, lighting profiles and light-color. We demonstrate the OptoArm’s power in a population-based study on contributions of motor circuit cells to age-related motility decline. We find that functional decline of cholinergic neurons mirrors motor decline, while GABAergic neurons and muscle cells are relatively age-resilient, suggesting that rate-limiting cells exist and determine neuronal circuit aging.

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“…Figure 2 shows the measured light output power as a function of the injection current for these three fabricated LED structures. In order to avoid the effects of self-heating, we applied pulse-width-modulated injection currents on each of the measured LEDs [22]. By increasing the injection current, the light output powers of these three fabricated LED under an injection current of 100 mA, respectively.…”

Section: Methodsmentioning

confidence: 99%

Investigating the Effect of Piezoelectric Polarization on GaN-Based LEDs with Different Prestrain Layer by Temperature-Dependent Electroluminescence

Wang

Chiou²,

Chiang³

et al. 2015

International Journal of Photoenergy

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The effect of piezoelectric polarization on GaN-based light emitting diodes (LEDs) with different kinds of prestrain layers between the multiple quantum wells (MQWs) and n-GaN layer is studied and demonstrated. Compared with the conventional LED, more than 10% enhancement in the output power of the LED with prestrain layer can be attributed to the reduction of polarization field within MQWs region. In this study, we reported a simple method to provide useful comparison of polarization fields within active region in GaN-based LEDs by using temperature-dependent electroluminescence (EL) measurement. The results pointed out that the polarization field of conventional LED was stronger than that of the others due to larger variation of the wavelength transition position (i.e., blue-shift change to red-shift) from 300 to 350 K, and thus the larger polarization field must be effectively screened by injecting more carriers into the MQWs region.

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Temperature and thermal characteristics of InGaN/GaN vertical light-emitting diodes on electroplated copper

Cited by 20 publications

References 27 publications

Fabrication of Phosphor-Free III-Nitride Nanowire Light-Emitting Diodes on Metal Substrates for Flexible Photonics

Fabrication of Phosphor-Free III-Nitride Nanowire Light-Emitting Diodes on Metal Substrates for Flexible Photonics

Optogenetic manipulation of individual or whole populationCaenorhabditis elegansworms with an under hundred-dollar tool: the OptoArm

Investigating the Effect of Piezoelectric Polarization on GaN-Based LEDs with Different Prestrain Layer by Temperature-Dependent Electroluminescence

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