&lt;title&gt;High-brightness AlGaInN light-emitting diodes&lt;/title&gt;

Krames, Michael R.; Christenson, G.L.; Collins, Dave; Cook, Lou W.; Craford, M. G.; Edwards, A.; Fletcher, R. M.; Gardner, Nathan F.; Goetz, W.; Imler, W.; Johnson, Eric; Kern, R. S.; Khare, R. P.; Kish, F. A.; Lowery, C. H.; Ludowise, M. J.; Mann, Richard S.; Maranowski, M.; Maranowski, S. A.; Martin, P.; O'Shea, J.; Rudaz, Serge; Steigerwald, D. A.; Thompson, J.; Wierer, Jonathan J.; Yu, J. G.; Basile, David P.; Chang, Ying‐Lan; Hasnain, G.; Heuschen, M.; Killeen, Kevin; Kocot, Chris; Lester, S.; Miller, J. N.; Mueller, Gerd; Mueller‐Mach, Regina; Rosner, S. J.; Schneider, Richard; Takeuchi, Tetsuya; Tan, Tun S.

doi:10.1117/12.382822

Cited by 29 publications

(7 citation statements)

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“…One coincidental advantage of performing radiometric tests at low If values is that parasitic luminescence is usually higher at low currents. Parasitic luminescence arises from deep-level defects (e.g., vacancies, impurities, dislocations) and can reduce quantum yield if present [20,21].…”

Section: Radiometric Measurementsmentioning

confidence: 99%

Initial Benchmarks of UV LEDs and Comparisons with White LEDs

Davis¹,

Rountree²

2021

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Light-emitting diodes (LEDs) can emit radiation that spans the range from near infrared (IR) to all three bands of ultraviolet (UV) radiation (i.e., UV-A, UV-B, UV-C). These emission sources are fabricated by varying doping levels of the aluminum gallium indium nitride (AlGaInN) alloy system, which tunes the emission wavelength of the semiconductor. During the past 20 years, the blue LED, made from InGaN, has advanced technologically to the point that it now provides the backbone for the solid-state lighting revolution that is occurring in general illumination. With proper doping, the InGaN alloy system can be extended to UV-A emission wavelengths as low as 362 nanometers (nm); however, producing LEDs that emit in the UV-B and UV-C bands requires the use of AlGaN alloys. Unfortunately, AlGaN semiconductors are not at the same level of technological development as InGaN, and LEDs made from AlGaN suffer from a variety of inefficiencies arising from electrical and optical limitations of the current technology. This report is aimed at benchmarking the performance of UV LEDs across all three bands in an effort to understand the current state of the technology.UV sources have many industrial applications, and their total market exceeds $750 million. Examples of applications for UV sources include ink and polymer curing (primarily UV-A sources), medical treatments (primarily UV-B sources), and disinfection (primarily UV-C sources). While UV-A applications are the largest market today, the increased need for surface and air disinfection is expected to create a significant market opportunity for UV-C sources in the near future. The current technology most widely used for UV sources in all three bands is the mercury discharge lamp, which has moderate energy efficiency but also has a number of limitations including compatibility with compact form factors, long-term reliability, and end-oflife issues associated with disposing a glass tube containing mercury without creating environmental contamination. UV LEDs have the potential to displace mercury lamps in UV applications in much the same way that white LEDs have displaced fluorescent lamps in many commercial and residential lighting markets.The primary goal of this report is to benchmark the initial level of performance of a selection of commercial UV LEDs across all three bands (i.e., UV-A, UV-B, UV-C). To provide the initial performance benchmarks, a test matrix containing 13 different UV LED products was created in association with the LED Systems Reliability Consortium (LSRC). The products in this test matrix were all commercially available as of June 2021, and at least 22 samples of each product were tested. In addition, two common, commercial white LEDs were tested to provide a benchmark against blue-pumped white LEDs. Testing of the samples included electrical performance testing (e.g., current-voltage measurements) and photometric testing in a calibrated integrating sphere capable of measuring devices in the UV-A, UV-B, and UV-C bands. The electrical testing provid...

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Section: Radiometric Measurementsmentioning

confidence: 99%

Initial Benchmarks of UV LEDs and Comparisons with White LEDs

Davis¹,

Rountree²

2021

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“…Shih-Chun Ling, 1 Tien-Chang Lu, 1,2,a͒ Shih-Pang Chang, 1,3 Jun-Rong Chen, 1 Hao-Chung Kuo, 1 We investigated the electroluminescence and relatively external quantum efficiency ͑EQE͒ of m-plane InGaN/GaN light emitting diodes ͑LEDs͒ emitting at 480 nm to elucidate the droop behaviors in nitride-based LEDs. With increasing the injection current density to 100 A / cm 2 , the m-plane LEDs exhibit only 13% efficiency droop, whereas conventional c-plane LEDs suffer from efficiency droop at very low injection current density and the EQE of c-plane LEDs decrease to as little as 50% of its maximum value.…”

Section: Low Efficiency Droop In Blue-green M-plane Ingan/gan Light Ementioning

confidence: 99%

“…1,2 This phenomenon, well known as efficiency droop, becomes more severe while the peak emission wavelength of LEDs further increases from UV spectral range toward blue and green spectral range. 1,2 This phenomenon, well known as efficiency droop, becomes more severe while the peak emission wavelength of LEDs further increases from UV spectral range toward blue and green spectral range.…”

Section: Low Efficiency Droop In Blue-green M-plane Ingan/gan Light Ementioning

confidence: 99%

Low efficiency droop in blue-green m-plane InGaN/GaN light emitting diodes

Ling

Lu²,

Chang

et al. 2010

Applied Physics Letters

154

107

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We investigated the electroluminescence and relatively external quantum efficiency (EQE) of m-plane InGaN/GaN light emitting diodes (LEDs) emitting at 480 nm to elucidate the droop behaviors in nitride-based LEDs. With increasing the injection current density to 100 A/cm2, the m-plane LEDs exhibit only 13% efficiency droop, whereas conventional c-plane LEDs suffer from efficiency droop at very low injection current density and the EQE of c-plane LEDs decrease to as little as 50% of its maximum value. Our simulation models show that in m-plane LEDs the absence of polarization fields manifest not only the hole distribution more uniform among the wells but also the reduction in electron overflow out of electron blocking layer. These results suggest that the nonuniform distribution of holes and electron leakage current due to strong polarization fields are responsible for the relatively significant efficiency droop of conventional c-plane LEDs.

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“…Normally, the current density corresponding to the peak IQE, J max , is less than 10 A/cm 2 [3]. GaN-based laser diodes (LDs) operate like LEDs before lasing and their efficiency droop phenomenon has also been studied [4,5,6].…”

Section: Introductionmentioning

confidence: 99%

“…Efficiency droop phenomenon has been widely observed in III-nitride light-emitting diodes (LEDs) [ 1 , 2 ], which means that the internal quantum efficiency (IQE) of GaN-based LEDs increases with the injection current until it comes to the maximum, afterwards it drops steadily. Normally, the current density corresponding to the peak IQE, J max , is less than 10 A/cm 2 [ 3 ]. GaN-based laser diodes (LDs) operate like LEDs before lasing and their efficiency droop phenomenon has also been studied [ 4 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

A Study of Efficiency Droop Phenomenon in GaN-Based Laser Diodes before Lasing

et al. 2017

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Carrier recombination behavior in c-plane GaN-based laser diodes (LDs) is numerically investigated by using the commercial software LASTIP. It is found that efficiency droop phenomenon does exist in GaN-based LDs before lasing, which is confirmed by experimental results. However, the current density corresponding to the peak efficiency of GaN-based LDs before lasing, Jmax, is nearly 40 A/cm2, which is much lower than that reported by other studies. The reported Jmax, measured from the cavity facet side is modulated by the absorption of quantum wells, which shifts the Jmax to a higher value. In addition, the currents due to various recombinations are calculated. It is found that Auger recombination affects the threshold current greatly, but it only plays a small role at high current injection levels.

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<title>High-brightness AlGaInN light-emitting diodes</title>

Cited by 29 publications

References 0 publications

Initial Benchmarks of UV LEDs and Comparisons with White LEDs

Initial Benchmarks of UV LEDs and Comparisons with White LEDs

Low efficiency droop in blue-green m-plane InGaN/GaN light emitting diodes

A Study of Efficiency Droop Phenomenon in GaN-Based Laser Diodes before Lasing

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