Is Auger recombination responsible for the efficiency rollover in III‐nitride light‐emitting diodes?

Bulashevich, K. A.; Karpov, S. Yu.

doi:10.1002/pssc.200778414

Cited by 96 publications

(59 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The order of magnitude of our A and C values is indeed in general agreement with several simulation studies discussing Auger effects on LED droop 3,4,23,24,47,107 and recent experimental studies on Auger recombination, focusing on its temperature 108 and composition 65,66 dependence and reaffirming the importance of Auger processes in the blue spectral range. Notably, the Augerlike coefficient determined in the present LED study is increasing with temperature, i.e.…”

Section: Auger Recombination and Auger-related Processessupporting

confidence: 91%

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

et al. 2014

View full text Add to dashboard Cite

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

show abstract

Section: Auger Recombination and Auger-related Processessupporting

confidence: 91%

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

et al. 2014

View full text Add to dashboard Cite

show abstract

“…We attribute the quantitative differences between our work and that of Bertazzi et al [63] to the different band structures (fully first-principles in pure GaN versus fitted pseudopotentials for virtual-crystal InGaN) and dielectric-function models used in the respective calculations. Finally, in the 1.0-1.5 eV energy range, the e-e-h coefficient increases exponentially for decreasing band-gap values, as expected for direct Auger recombination [64], because only direct intraband Auger transitions are possible for this band-gap range.…”

Section: A Direct Auger Recombination In Gansupporting

confidence: 54%

First-principles calculations of indirect Auger recombination in nitride semiconductors

et al. 2015

View full text Add to dashboard Cite

Auger recombination is an important nonradiative carrier recombination mechanism in many classes of optoelectronic devices. The microscopic Auger processes can be either direct or indirect, mediated by an additional scattering mechanism such as the electron-phonon interaction and alloy disorder scattering. Indirect Auger recombination is particularly strong in nitride materials and affects the efficiency of nitride optoelectronic devices at high powers. Here, we present a first-principles computational formalism for the study of direct and indirect Auger recombination in direct-band-gap semiconductors and apply it to the case of nitride materials. We show that direct Auger recombination is weak in the nitrides and cannot account for experimental measurements. On the other hand, carrier scattering by phonons and alloy disorder enables indirect Auger processes that can explain the observed loss in devices. We analyze the dominant phonon contributions to the Auger recombination rate and the influence of temperature and strain on the values of the Auger coefficients. Auger processes assisted by charged-defect scattering are much weaker than the phonon-assisted ones for realistic defect densities and not important for the device performance. The computational formalism is general and can be applied to the calculation of the Auger coefficient in other classes of optoelectronic materials.

show abstract

“…At the active layer thickness of ~3-5 nm the electron and hole concentrations become nearly equal to each other, and IQE decreases, peaking at ~10-20 A/cm 2 . The latter correlates well with numerous measurements of the LED external quantum efficiency (see, for instance, the data compiled in [2]). …”

mentioning

confidence: 67%

Assessment of various LED structure designs for high‐current operation

Bulashevich¹,

Ramm²,

Karpov³

2009

Phys. Status Solidi (c)

Self Cite

View full text Add to dashboard Cite

Using modelling, we have examined alternative designs of light‐emitting diode (LED) structures, aimed at lowering the non‐equilibrium carrier concentration and, hence, at suppression of Auger recombination in the active regions of the diodes. Both a multi‐quantum‐well (MQW) heterostructure and that with a thick single active layer are compared. The MQW structure is found to be ineffective for improvement of the LED internal quantum efficiency (IQE). In contrast, LEDs with a thick single active layer turn out to be quite promising for high‐current operation. Detailed simulation provides a guideline for further optimization of the LED heterostructures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Is Auger recombination responsible for the efficiency rollover in III‐nitride light‐emitting diodes?

Cited by 96 publications

References 13 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

First-principles calculations of indirect Auger recombination in nitride semiconductors

Assessment of various LED structure designs for high‐current operation

Contact Info

Product

Resources

About