Effects of the number of quantum wells on the performance of near-ultraviolet light-emitting diodes

Choi, Hyun-Woong; Zheng, Dong-Guang; Kim, Hyunsung; Shim, Jong‐In; Shin, Dong Soo

doi:10.3938/jkps.66.1554

Cited by 6 publications

(2 citation statements)

References 13 publications

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“…42 In another study of the effect of increasing the number of QWs from 5 to 7 in 380-nm UV-LEDs, Choi et al found that the systematic changes they observed in the optical and electrical characteristics were best described by assuming uniform distributions of electrons and holes across the MQW. 43 The conclusion that nearly uniform distributions of electrons and holes occur across the MQW, does not necessarily conflict with experiments in which a QW emitting at a longer wavelength has been used to identify the location in a MQW from which light is predominantly emitted. 23 The presence of a deeper or wider QW in a superlattice or MQW will both introduce electron and hole states localized to the different wells and disrupt the formation of the quasi-extended states by which free carriers would otherwise spread through the MQW by thermally-assisted tunneling.…”

Section: -5mentioning

confidence: 99%

The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes

Hopkins

Allsopp

Kappers

et al. 2017

Journal of Applied Physics

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The efficiency of light emitting diodes (LEDs) remains a topic of great contemporary interest due to their potential to reduce the amount of energy consumed in lighting. The current consensus is that electrons and holes distribute themselves through the emissive region by a drift-diffusion process which results in a highly non-uniform distribution of the light emission and can reduce efficiency. In this paper, the measured variations in the external quantum efficiency of a range of InGaN/GaN LEDs with different numbers of quantum wells (QWs) are shown to compare closely with the predictions of a revised ABC model, in which it is assumed that the electrically injected electrons and holes are uniformly distributed through the multi-quantum well (MQW) region, or nearly so, and hence carrier recombination occurs equally in all the quantum wells. The implications of the reported results are that drift-diffusion plays a far lesser role in cross-well carrier transport than previously thought; that the dominant cause of efficiency droop is intrinsic to the quantum wells and that reductions in the density of non-radiative recombination centers in the MQW would enable the use of more QWs and thereby reduce Auger losses by spreading carriers more evenly across a wider emissive region. V

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Section: -5mentioning

confidence: 99%

The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes

Hopkins

Allsopp

Kappers

et al. 2017

Journal of Applied Physics

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“…There are seldom works to study the effect of quantum well (QW) number on the electron overflow in DUV-LEDs. It has been reported that with the increase in InGaN QW number from 5 to 7, the external quantum efficiency (EQE) was increased by 30.4% [22]. However, when the QW number increased to more than 15, the photoluminescence intensity of InGaN/GaN MQWs decreased significantly due to the relaxation of an accumulated strain through the dislocations induced by an increase in the total thickness of the MQWs [23].…”

Section: Introductionmentioning

confidence: 99%

Influence of Quantum-Well Number and an AlN Electron Blocking Layer on the Electroluminescence Properties of AlGaN Deep Ultraviolet Light-Emitting Diodes

et al. 2018

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The influence of quantum-well (QW) number on electroluminescence properties was investigated and compared with that of AlN electron blocking layer (EBL) for deep ultraviolet light-emitting diodes (DUV-LEDs). By increasing the QW number, the band emission around 265 nm increased and the parasitic peak around 304 nm was suppressed. From the theoretical calculation, the electron current overflowing to the p-type layer was decreased as the QW number increased under the same injection. Correspondingly, the light output power also increased. The increment of output power from 5 QWs to 10 QWs was less than that from 10 QWs to 40 QWs, which was very different from what has been reported for blue and near-UV LEDs. The parasitic peak was still observed even when the QW number increased to 40. However, it can be suppressed efficiently by 1 nm AlN EBL for LEDs with 5 QWs. The simulation showed that the insertion of a thin EBL increased the barrier height for electron overflow and the electron current in p-type layers decreased significantly. The results contributed to the understanding of behavior of electron overflow in DUV-LEDs.

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Electroluminescence study of InGaN/GaN QW based p-i-n and inverted p-i-n junction based short-wavelength LED device using laser MBE technique

2022

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Effects of the number of quantum wells on the performance of near-ultraviolet light-emitting diodes

Cited by 6 publications

References 13 publications

The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes

The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes

Influence of Quantum-Well Number and an AlN Electron Blocking Layer on the Electroluminescence Properties of AlGaN Deep Ultraviolet Light-Emitting Diodes

Electroluminescence study of InGaN/GaN QW based p-i-n and inverted p-i-n junction based short-wavelength LED device using laser MBE technique

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