Simulation of visible and ultra-violet group-III nitride light emitting diodes

Bulashevich, K. A.; Mymrin, V. F.; Karpov, S. Yu.; Zhmakin, I. A.; Zhmakin, Alexander I.

doi:10.1016/j.jcp.2005.08.011

Cited by 62 publications

(33 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…4 Available data on the current-voltage characteristics indicate, however, that at high injection, a leakage current ͑here identified as a tunneling current͒ is strong in these LEDs, which cannot be modeled within the SRH framework. This tunneling current appears to correlate with a high dislocation density.…”

mentioning

confidence: 98%

“…1,3 Several reasons for this behavior have been discussed recently, such as a high device temperature, 4 restricted hole injection, 5 or carrier overflow problems. 3 The role of defects as being responsible for the drop in IQE has not been seriously discussed, despite the very high threading dislocation density in the present LEDs.…”

mentioning

confidence: 99%

“…3,6 In recent simulations based on the conventional Shockley-Read-Hall defect recombination scheme for the nonradiative part, it is found that such recombination is insufficient to explain the decrease observed in the IQE at high bias. 4,5 In this paper, we will concentrate on two problems of relevance for a modeling of this decrease of the IQE in InGaN based LEDs. A description of the influence of the screening by injected carriers on the localization potentials, 7 which has been largely ignored in the literature, is discussed.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Defect related issues in the “current roll-off” in InGaN based light emitting diodes

Ḿonemar¹,

Sernelius²

2007

Applied Physics Letters

286

160

View full text Add to dashboard Cite

Defect related contributions to the reduction of the internal quantum efficiency of InGaN-based multiple quantum well light emitting diodes under high forward bias conditions are discussed. Screening of localization potentials for electrons is an important process to reduce the localization at high injection. The possible role of threading dislocations in inducing a parasitic tunneling current in the device is discussed. Phonon-assisted transport of holes via tunneling at defect sites along dislocations is suggested to be involved, leading to a nonradiative parasitic process enhanced by a local temperature rise at high injection.

show abstract

mentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Defect related issues in the “current roll-off” in InGaN based light emitting diodes

Ḿonemar¹,

Sernelius²

2007

Applied Physics Letters

286

160

View full text Add to dashboard Cite

show abstract

“…To investigate and compare the operation of the DHJ and LHJ structures described in the previous paragraphs, we solve the standard drift-diffusion model relating the electrostatic potential φ and the electron and hole current densities J J J J , the electron and hole densities p and n, the ionized donor and acceptor densities N d and N a , the polarization density P P tot consisting of spontaneous and piezoelectric polarization and the conduction and valence band quasi-Fermi levels E Fn and E Fp as well as the net recombination rate density R. [16] Quantitatively the drift-diffusion model is given by…”

mentioning

confidence: 99%

Elimination of Lateral Resistance and Current Crowding in Large‐Area LEDs by Composition Grading and Diffusion‐Driven Charge Transport

Kivisaari

Kim

Suihkonen

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

from the resistance of the CSL, and they also reduce the effective area of the ohmic contacts and further aggravate the droop.To mitigate the effects of the resistive losses, Hurni et al. recently showed that increasing the thickness of the n-type CSL leads to significantly less pronounced current crowding and improves the wall-plug efficiency of LEDs at large currents. [8] However, this approach still necessitates using expensive bulk GaN substrates and a part of the active region (AR) needs to be cut out to deposit n-type contacts, exposing the edges of the AR to surface recombination. The basic structure of Hurni's low resistance LEDs as well as essentially all conventional LEDs relies on a double heterojunction (DHJ) design, where electrons and holes are injected to the AR from nand p-doped regions located on the opposite sides of the AR. This sets evident limitations to designing the structures so that the contacts do not substantially decrease the total AR area or increase the free surface area susceptible to surface recombination. To avoid some of the limitations of conventional DHJ structures related to device scaling, resistive losses and electrical excitation in general, diffusion-driven charge transport (DDCT) was very recently introduced as an alternative way to electrically excite the AR of LEDs. [9][10][11][12] In DDCT, the pn junction is partly separated from the AR, and in contrast with conventional solutions it relies on transporting electrons and holes to the AR from the same side by bipolar diffusion, enabling additional degrees of freedom for designing new devices.For practical reasons, the previous works on DDCT have mainly focused on structures containing vertically formed pn-homojunctions, which entail potential barriers and lead to suboptimal device performance. In this paper, however, we show that the electrical inefficiencies observed earlier can be fully eliminated by adapting the DDCT concept to realize laterally doped heterojunction (LHJ) structures (see Figure 1), and that the SAG techniques needed to realize such LHJ devices do not compromise the internal quantum efficiency of the AR. Furthermore, our results show that the LHJ structures can be further engineered using appropriate material composition gradings, that can reduce the resistive heating of the devices even below the limit set by ideal conventional DHJ devices.The fundamental difference between the DHJ and LHJ structures is the placement and geometry of the doped p-and n-GaN charge injection regions, which are expected to mainly affect Gallium nitride based light-emitting diodes (LEDs) are presently fundamentally transforming the lighting industry, but limitations in the materials and fabrication methods of LEDs introduce substantial challenges to their future development. Among the remaining key bottlenecks of GaN LEDs are the resistive losses and current crowding that strongly increase the heat generation at high powers. In this work the authors show how a new design paradigm based on diffusion-driven charge transport (...

show abstract

“…Использование представлений о квазиравновесном со-стоянии системы, положенных в основу диффузионно-дрейфовой модели переноса заряда в структурах с КЯ InGaN/GaN [27,28], не позволяет объяснить инверсию температурой зависимости КВ вследствие утечки. Глав-ным образом это связано с экспоненциальным сниже-нием вероятности термического выброса электронов из квантовых ям при уменьшении температуры.…”

Section: низкотемпературные потериunclassified

Влияние баллистической утечки на температурную зависимость квантового выхода светодиодов на основе множественных квантовых ям InGaN/GaN

Prudaev¹,

Kop’ev²,

Romanov³

et al. 2017

Физика И Техника Полупроводников

View full text Add to dashboard Cite

В работе исследованы зависимости квантового выхода от температуры и уровня возбуждения для светодиодов на основе множественных квантовых ям InGaN/GaN. Эксперимент проводился для двух режимов возбуждения люминесценции. Сравнение результатов, полученных при фото- и электролюминесценции, показало, что в области высокой плотности тока наблюдаются дополнительные низкотемпературные потери (дополнительные к потерям, связанным с оже-рекомбинацией). Это обусловливает инверсию температурной зависимости квантового выхода при температурах меньше 220-300 K. В результате анализа установлено, что потери связаны с утечкой электронов из активной области светодиода. Для объяснения экспериментальных данных привлечена модель баллистической утечки. Результаты моделирования качественно согласуются с экспериментальными зависимостями квантового выхода от температуры и плотности тока. DOI: 10.21883/FTP.2017.02.44112.8251

show abstract

Simulation of visible and ultra-violet group-III nitride light emitting diodes

Cited by 62 publications

References 77 publications

Defect related issues in the “current roll-off” in InGaN based light emitting diodes

Defect related issues in the “current roll-off” in InGaN based light emitting diodes

Elimination of Lateral Resistance and Current Crowding in Large‐Area LEDs by Composition Grading and Diffusion‐Driven Charge Transport

Влияние баллистической утечки на температурную зависимость квантового выхода светодиодов на основе множественных квантовых ям InGaN/GaN

Contact Info

Product

Resources

About