Reliability issues in AlGaN based deep ultraviolet light emitting diodes

Khan, Asif; Hwang, Seongmo; Lowder, J.E.; Adivarahan, V.; Fareed, Q.

doi:10.1109/irps.2009.5173229

Cited by 12 publications

(8 citation statements)

References 15 publications

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“…6 This high DD limits both the efficiency and the reliability of devices grown on such layers. 7,8 An alternative and also possibly the best approach for reducing the DD is the use of a low defect AlN substrate. 9 Currently, physical vapour transport (PVT -also known as the sublimation-recondensation method) is the most successful and widely used method for producing large area AlN native substrates.…”

Section: Introductionmentioning

confidence: 99%

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Sumathi

2013

CrystEngComm

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Physical vapour transport growth of aluminium nitride (AlN) single crystals on silicon carbide (SiC) substrates has been optimised and crack-free, large-area, free-standing (0001) AlN wafers were prepared from the grown template crystals. 28 mm diameter single crystals without any polycrystalline surroundings were obtained. Different off-oriented substrates give rise to different growth modes. Sharp and symmetric line shapes of X-ray diffraction (XRD) rocking curves and high intense Raman phonon mode peaks prove high structural quality and homogeneity of the grown crystals. Full width at half maximum of the rocking curves is 72 arcsec for symmetric 00. demonstrates that AlN templates prepared on SiC as a foreign substrate can be used as native seeds for the growth of further homo-epitaxial layers and crystalline boules.

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Section: Introductionmentioning

confidence: 99%

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Sumathi

2013

CrystEngComm

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“…However, currently devices are fabricated from Al x Ga 1-x N layers on sapphire substrates which lead to a high dislocation density and thus low efficiencies and short lifetimes [2]. Bulk AlN substrates offer several advantages over growth on sapphire, including low lattice and thermal mismatch between the substrate and the device layers.…”

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confidence: 99%

Performance and reliability of ultraviolet‐C pseudomorphic light emitting diodes on bulk AlN substrates

Grandusky

Cui

Gibb

et al. 2010

Phys. Status Solidi (c)

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Low dislocation density, epitaxial layers of AlxGa1–xN are grown pseudomorphically on native AlN substrates prepared from high quality, bulk crystals. In addition to low dislocation density, they are atomically smooth and can be doped n‐type to obtain sheet resistances < 200 Ohms/sq/μm. These layers are used as templates for the growth of high quality multiple quantum well (MQW) structures and ultraviolet (UV) light emitting diodes (LED). The pseudomorphic growth and atomically smooth surfaces are achieved for a full device structure. Previously we have demonstrated the high optical quality of these structures through temperature dependant photoluminescence measurements and X‐ray diffraction. Recently full device structures have been fabricated and packaged. These devices, with emission wavelength between 250 nm and 280 nm show linear increase in output power as a function of current up to 150 mA in thermal equilibrium. Additionally output powers up to 1.3 mW have been achieved at 258 nm at 400 mA drive current. Reliability of the devices has been measured for 1000 hours with expected lifetimes greater than 3000 hours for input currents up to 150 mA (with an average current density of approximately 150 A/cm2). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…The current crowding and the series resistance can be reduced by using micro-pixel electrode structure, which can help decrease the junction temperature and prolong the lifetime effectively. [90] We have also studied the reliability of commercial deep UV LEDs using in situ accelerated aging test systems and different analytical technologies. [91][92][93] The failure analysis shows that both point defects and dislocations exist after the degradation, as shown in Figure 7.…”

Section: Algan-based Deep Uv Ledsmentioning

confidence: 99%

Progress of Reliability and Failure Mechanisms for GaN‐Based Light‐Emitting Diodes

Zhao

Liu

2022

Physica Status Solidi (a)

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To achieve high reliable GaN-based LEDs with a controllable lifetime is one of the key issues for applications. In this review, an overview of reliability studies for different GaN-based LEDs, especially the research progress in our group based on our specially designed in situ multifunctional highly accelerated aging test system over the past few years, is presented. The contents not only cover highpower GaN-based LEDs, mid-power GaN-based LEDs, deep UV GaN-based LEDs, micro-LEDs, and phosphors under different operating conditions but also include the influence of point defects on the degradation, the correlation between luminous flux and color quality, and so on. Finally, prospects for reliability are discussed with the further development of the GaN-based devices.

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Reliability issues in AlGaN based deep ultraviolet light emitting diodes

Cited by 12 publications

References 15 publications

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds

Performance and reliability of ultraviolet‐C pseudomorphic light emitting diodes on bulk AlN substrates

Progress of Reliability and Failure Mechanisms for GaN‐Based Light‐Emitting Diodes

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