Control of quantum-confined Stark effect in InGaN∕GaN multiple quantum well active region by p-type layer for III-nitride-based visible light emitting diodes

Ryou, Jae‐Hyun; Lee, W.; Limb, J.; Yoo, Dongwon; Liu, J. P.; Dupuis, R. D.; Wu, Zhihao; Fischer, Alec M.; Ponce, Fernando

doi:10.1063/1.2894514

Cited by 63 publications

(37 citation statements)

References 19 publications

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“…This results in a large redshift of the transition energy with respect to a flat-band case (so-called Quantum Confined Stark Effect (QCSE)) and in a spatial separation of the electrons and holes reducing the emission rate [18,19,20,21,22,23,24,25]. When the charge carrier density increases, non-linearities are expected [19,26,27,28,29,30,31] as charge carriers screen the internal field and thus reduce the redshift and increase the emission rate. On the other hand, the increase in charge carrier density leads to the upturn of high order phenomena such as the Auger effect (the non-radiative recombination of an electron-hole pair with an energy transfer to a third charge in their vicinity), which are deleterious for the emission properties [12].…”

Section: Introductionmentioning

confidence: 99%

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

et al. 2016

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We report on a detailed study of the intensity dependent optical properties of individual GaN/AlN Quantum Disks (QDisks) embedded into GaN nanowires (NW). The structural and optical properties of the QDisks were probed by high spatial resolution cathodoluminescence (CL) in a scanning transmission electron microscope (STEM). By exciting the QDisks with a nanometric electron beam at currents spanning over 3 orders of magnitude, strong non-linearities (energy shifts) in the light emission are observed. In particular, we find that the amount of energy shift depends on the emission rate and on the QDisk morphology (size, position along the NW and shell thickness). For thick QDisks (>4nm), the QDisk emission energy is observed to blue-shift with the increase of the emission intensity. This is interpreted as a consequence of the increase of carriers density excited by the incident electron beam inside the QDisks, which screens the internal electric field and thus reduces the quantum confined Stark effect (QCSE) present in these QDisks. For thinner QDisks (<3 nm), the blue-shift is almost absent in agreement with the negligible QCSE at such sizes. For QDisks of intermediate sizes there exists a current threshold above which the energy shifts, marking the transition from unscreened to partially screened QCSE. From the threshold value we estimate the lifetime in the unscreened regime. These observations suggest that, counterintuitively, electrons of high energy can behave ultimately as single electron-hole pair generators. In addition, when we increase the current from 1 pA to 10 pA the light emission efficiency drops by more than one order of magnitude. This reduction of the emission efficiency is a manifestation of the 'efficiency droop' as observed in nitride-based 2D light emitting diodes, a phenomenon tentatively attributed to the Auger effect. *

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Section: Introductionmentioning

confidence: 99%

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

et al. 2016

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“…5 Hence, there is a need to study and understand the effect of the enhanced indium composition and QCSE on the LED performance. 6 In this work, the redshift of emission wavelength was investigated in the InGaN/GaN blue LEDs grown under the same QW growth conditions but with a higher growth temperature of interlayer. The effects of the enhanced indium composition and QCSE on the performance of these LEDs were studied both experimentally and theoretically.…”

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confidence: 99%

On the origin of the redshift in the emission wavelength of InGaN/GaN blue light emitting diodes grown with a higher temperature interlayer

Tan

Zhang

et al. 2012

Applied Physics Letters

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Cataloged from PDF version of article.A redshift of the peak emission wavelength was observed in the blue light emitting diodes of InGaN/GaN grown with a higher temperature interlayer that was sandwiched between the low-temperature buffer layer and high-temperature unintentionally doped GaN layer. The effect of interlayer growth temperature on the emission wavelength was probed and studied by optical, structural, and electrical properties. Numerical studies on the effect of indium composition and quantum confinement Stark effect were also carried out to verify the experimental data. The results suggest that the redshift of the peak emission wavelength is originated from the enhanced indium incorporation, which results from the reduced strain during the growth of quantum wells. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694054

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“…We report on the effect on the hole transport and resulting hole distribution by controlling indium (In) mole fraction in p-type In x Ga 1−x N:Mg layers of LED structures. p-InGaN layers replacing p-GaN have been demonstrated to result in reduced thermal damage to "true"-green MQW active region [15] and mitigation of the quantum-confined Stark effect (QCSE) [16]. In addition to those beneficial effects, enhanced hole transport in the MQW active region is demonstrated in this letter.…”

Section: Introductionmentioning

confidence: 91%

Improved Hole Transport by ${\rm p}\hbox{-}{\rm In}_{x}{\rm Ga}_{1-x}{\rm N}$ Layer in Multiple Quantum Wells of Visible LEDs

Kim

Lochner

et al. 2013

IEEE Photon. Technol. Lett.

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Studied is the effect of indium (In) mole fraction in p-In x Ga 1−x N:Mg layers with 0 ≤ x In ≤ 0.035 on hole injection and transport behaviors in InGaN/GaN multiple quantum wells (MQWs) using dual-wavelength and triple-wavelength active regions. Electro-optical characteristics of light-emitting diodes containing p-layers with different In content and with silicon doping in selected QW barriers (QWBs) are compared to evaluate hole transport in the active region. The results show that enhanced hole transport and corresponding more uniform distribution of holes across the MQW region are achieved by increasing x In in the p-In x Ga 1−x N:Mg layer, possibly due to modification in energy of holes by a potential barrier between the p-InGaN and GaN QWB.

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Control of quantum-confined Stark effect in InGaN∕GaN multiple quantum well active region by p-type layer for III-nitride-based visible light emitting diodes

Cited by 63 publications

References 19 publications

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

On the origin of the redshift in the emission wavelength of InGaN/GaN blue light emitting diodes grown with a higher temperature interlayer

Improved Hole Transport by ${\rm p}\hbox{-}{\rm In}_{x}{\rm Ga}_{1-x}{\rm N}$ Layer in Multiple Quantum Wells of Visible LEDs

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