Correlation between defect properties and internal quantum efficiency in blue-emitting InGaN based light emitting diodes

Lee, Sun-Kyun; Lim, Hyun Kyoung; Lee, Jang-Ho; Kwack, Ho-Sang; Cho, Hyun Kyong; Kwon, Hansang; Oh, Myeong Seok

doi:10.1063/1.4720447

Cited by 3 publications

(2 citation statements)

References 24 publications

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“…67 and 68, while the A coefficient was assumed to be roughly proportional to N disl 69 (see also the recent studies on the impact of TDD on LED efficiency presented in Refs. 63,[70][71][72][73][74][75][76]. Auger coefficients were not forced to be the same in LDD and HDD LEDs because, although nominally identical, secondary ion mass spectrometry (SIMS) measures suggest that the QWs of the LDD devices have probably a smoother profile, which could imply a lower Auger rate.…”

Section: D Simulation Studymentioning

confidence: 99%

Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

et al. 2014

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Electroluminescence (EL) characterization of InGaN/GaN light-emitting diodes (LEDs), coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of currentand temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs). First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional) classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i) the approximations in the transport description through the multi-quantum-well active region, (ii) the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii) the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10−30 cm6/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary attempt at uncertainty quantification confirms, beyond the present case, the need for an improved description of carrier transport and microscopic radiative and nonradiative recombination mechanisms in device-level LED numerical models

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Section: D Simulation Studymentioning

confidence: 99%

Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

et al. 2014

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“…Table 1 shows the fitted values of the Arrhenius parameters for all samples. It is reasonable to assume that the first nonradiative channel could be ascribed to the conventional thermal decay process induced by the thermally activated nonradiative recombination centers, which often originate from the point or extended crystal defects in InGaN alloys [28]. Generally, the thermal activation energy E 1 of the first nonradiative channel is determined by the nonradiative capturing process of charge carriers, which is closely related to the concentration, types, and characteristics of crystal defects [29].…”

Section: Resultsmentioning

confidence: 99%

Reduction in the Photoluminescence Intensity Caused by Ultrathin GaN Quantum Barriers in InGaN/GaN Multiple Quantum Wells

et al. 2022

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The optical properties of InGaN/GaN violet light-emitting multiple quantum wells with different thicknesses of GaN quantum barriers are investigated experimentally. When the barrier thickness decreases from 20 to 10 nm, the photoluminescence intensity at room temperature increases, which can be attributed to the reduced polarization field in the thin-barrier sample. However, with a further reduction in the thickness to 5 nm, the sample’s luminescence intensity decreases significantly. It is found that the strong nonradiative loss process induced by the deteriorated crystal quality and the quantum-tunneling-assisted leakage of carriers may jointly contribute to the enhanced nonradiative loss of photogenerated electrons and holes, leading to a significant reduction in photoluminescence intensity of the sample with nanoscale ultrathin GaN quantum barriers.

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Physical properties of indium nitride, impurities, and defects

2014

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Correlation between defect properties and internal quantum efficiency in blue-emitting InGaN based light emitting diodes

Cited by 3 publications

References 24 publications

Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

Reduction in the Photoluminescence Intensity Caused by Ultrathin GaN Quantum Barriers in InGaN/GaN Multiple Quantum Wells

Physical properties of indium nitride, impurities, and defects

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