Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes
The efficiency droop characteristics of single quantum well (SQW) InGaN/GaN light-emitting diodes (LEDs) including the phase-space filling (PSF) effect are predicted by a three-dimensional (3-D) numerical simulation. The carrier transport is based on the solution of the 3-D non-linear Poisson and dr...
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doaj-19faf865f50949a99178152cc891ecd52021-03-29T17:52:04ZengIEEEIEEE Photonics Journal1943-06552019-01-0111111710.1109/JPHOT.2019.28931988613781Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting DiodesQuoc-Hung Pham0https://orcid.org/0000-0001-9642-3232Jyh-Chen Chen1https://orcid.org/0000-0002-6716-0741Huy-Bich Nguyen2Department of Mechanical Engineering, National Central University, Jhongli City, TaiwanDepartment of Mechanical Engineering, National Central University, Jhongli City, TaiwanDepartment of Mechanical Engineering, Nong Lam University, Ho Chi Minh City, VietnamThe efficiency droop characteristics of single quantum well (SQW) InGaN/GaN light-emitting diodes (LEDs) including the phase-space filling (PSF) effect are predicted by a three-dimensional (3-D) numerical simulation. The carrier transport is based on the solution of the 3-D non-linear Poisson and drift-diffusion equations for both holes and electrons. A modified formulation of the Shockley-Reed-Hall (SRH) coefficient is proposed to describe the SRH carrier lifetime behavior, which increases at a low excitation level and decreases at a higher one. The current crowding causes a non-uniform distribution of the carrier concentration in the active layer that leads to the inversion of the local internal quantum efficiency (IQE) under the n-pad region when the injection current density increases from low to high levels. To further understand the correlation of the efficiency droop with the PSF effect, we systematically investigate carrier transport in the SQW InGaN/GaN LEDs and how the different PSF effect coefficients affect the current-voltage curve and IQE. The lumped IQE found in this study agrees well with previous experimental measurements. Moreover, the PSF effect has a strong impact on the IQE behavior including its peak and droop in efficiency.https://ieeexplore.ieee.org/document/8613781/InGaN/GaNlight-emitting diodes (LEDs)optoelectronic devicesphase space filling (PSF) effectcurrent spreading |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Quoc-Hung Pham Jyh-Chen Chen Huy-Bich Nguyen |
spellingShingle |
Quoc-Hung Pham Jyh-Chen Chen Huy-Bich Nguyen Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes IEEE Photonics Journal InGaN/GaN light-emitting diodes (LEDs) optoelectronic devices phase space filling (PSF) effect current spreading |
author_facet |
Quoc-Hung Pham Jyh-Chen Chen Huy-Bich Nguyen |
author_sort |
Quoc-Hung Pham |
title |
Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes |
title_short |
Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes |
title_full |
Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes |
title_fullStr |
Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes |
title_full_unstemmed |
Three-Dimensional Numerical Study on the Efficiency Droop in InGaN/GaN Light-Emitting Diodes |
title_sort |
three-dimensional numerical study on the efficiency droop in ingan/gan light-emitting diodes |
publisher |
IEEE |
series |
IEEE Photonics Journal |
issn |
1943-0655 |
publishDate |
2019-01-01 |
description |
The efficiency droop characteristics of single quantum well (SQW) InGaN/GaN light-emitting diodes (LEDs) including the phase-space filling (PSF) effect are predicted by a three-dimensional (3-D) numerical simulation. The carrier transport is based on the solution of the 3-D non-linear Poisson and drift-diffusion equations for both holes and electrons. A modified formulation of the Shockley-Reed-Hall (SRH) coefficient is proposed to describe the SRH carrier lifetime behavior, which increases at a low excitation level and decreases at a higher one. The current crowding causes a non-uniform distribution of the carrier concentration in the active layer that leads to the inversion of the local internal quantum efficiency (IQE) under the n-pad region when the injection current density increases from low to high levels. To further understand the correlation of the efficiency droop with the PSF effect, we systematically investigate carrier transport in the SQW InGaN/GaN LEDs and how the different PSF effect coefficients affect the current-voltage curve and IQE. The lumped IQE found in this study agrees well with previous experimental measurements. Moreover, the PSF effect has a strong impact on the IQE behavior including its peak and droop in efficiency. |
topic |
InGaN/GaN light-emitting diodes (LEDs) optoelectronic devices phase space filling (PSF) effect current spreading |
url |
https://ieeexplore.ieee.org/document/8613781/ |
work_keys_str_mv |
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