Dependence of radiative efficiency and deep level defect incorporation on threading dislocation density for InGaN/GaN light emitting diodes

Armstrong, Andrew M.; Henry, Tania; Koleske, Daniel; Crawford, Mary H.; Westlake, Karl; Lee, Stephen R.

doi:10.1063/1.4759003

Cited by 59 publications

(34 citation statements)

References 16 publications

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“…But since the measurements are mostly done in the extrinsic excitation light range where the absorption coefficient is low the assumption of uniform excitation within the space charge region usually holds.) Such measurements were performed for MQW LED structures strongly differing by the dislocation density from 5.3 Â 10 8 to 2.9 Â 10 9 cm À2 [356]. External quantum efficiency measurements showed a much higher value for the lower dislocation density (see Fig.…”

Section: Deep Traps In Gan/ingan and Algan/algan Leds And Ldsmentioning

confidence: 98%

Deep traps in GaN-based structures as affecting the performance of GaN devices

Polyakov

Lee

2015

Materials Science and Engineering: R: Reports

213

177

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Section: Deep Traps In Gan/ingan and Algan/algan Leds And Ldsmentioning

confidence: 98%

Deep traps in GaN-based structures as affecting the performance of GaN devices

Polyakov

Lee

2015

Materials Science and Engineering: R: Reports

213

177

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“…[6][7][8] They have been shown to play a role in determining the quantum efficiency of LEDs and LDs and to take part in degradation occurring in these devices. [9][10][11][12] Not much is known regarding possible mechanisms of such dislocation-driven degradation. For MBE-grown LEDs, it has been reported that the loss of injection efficiency can be associated with the formation of dislocation bunches lying in the basal plane in the active region of the LEDs.…”

Section: Movement Of Basal Plane Dislocations In Gan During Electron mentioning

confidence: 99%

Movement of basal plane dislocations in GaN during electron beam irradiation

Yakimov

Вергелес

Polyakov

et al. 2015

Applied Physics Letters

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The movement of basal plane segments of dislocations in low-dislocation-density GaN films grown by epitaxial lateral overgrowth as a result of irradiation with the probing beam of a scanning electron microscope was detected by means of electron beam induced current. Only a small fraction of the basal plane dislocations was susceptible to such changes and the movement was limited to relatively short distances. The effect is explained by the radiation enhanced dislocation glide for dislocations pinned by two different types of pinning sites: a low-activation-energy site and a high-activation-energy site. Only dislocation segments pinned by the former sites can be moved by irradiation and only until they meet the latter pinning sites. V C 2015 AIP Publishing LLC.

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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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Dependence of radiative efficiency and deep level defect incorporation on threading dislocation density for InGaN/GaN light emitting diodes

Cited by 59 publications

References 16 publications

Deep traps in GaN-based structures as affecting the performance of GaN devices

Deep traps in GaN-based structures as affecting the performance of GaN devices

Movement of basal plane dislocations in GaN during electron beam irradiation

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

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