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On the Monte Carlo Description of Hot Carrier Effects and Device Characteristics of III-N LEDs

Kivisaari, Pyry LU ; Sadi, Toufik; Li, Jingrui; Rinke, Patrick and Oksanen, Jani (2017) In Advanced Electronic Materials
Abstract

Recent experiments have suggested that high energy charge carriers can have a significant effect on the operation of group III nitride (III-N) light-emitting diodes (LEDs), possibly playing an important role in the efficiency droop. As hot carriers are not accounted for by device simulation tools based on drift-diffusion (DD) and quasiequilibrium conditions, more advanced tools are needed. Here, fully self-consistent Monte Carlo (MC) simulations are developed to investigate the effects of hot carriers in device operation and to outline the shortcomings of the DD models in modeling multiquantum well (MQW) LEDs. The results show that hot carrier transport can lead to substantial electron overflow distributing the carriers more evenly in... (More)

Recent experiments have suggested that high energy charge carriers can have a significant effect on the operation of group III nitride (III-N) light-emitting diodes (LEDs), possibly playing an important role in the efficiency droop. As hot carriers are not accounted for by device simulation tools based on drift-diffusion (DD) and quasiequilibrium conditions, more advanced tools are needed. Here, fully self-consistent Monte Carlo (MC) simulations are developed to investigate the effects of hot carriers in device operation and to outline the shortcomings of the DD models in modeling multiquantum well (MQW) LEDs. The results show that hot carrier transport can lead to substantial electron overflow distributing the carriers more evenly in MQW structures, increasing the total recombination and leakage currents. Also Auger recombination is found to drive the distributions out of quasiequilibrium but, surprisingly, it does not contribute extensively to the leakage current. The simulations involve in-house ab-initio band structures as well as parameterized band structures, but qualitatively the results do not strongly depend on the band structure details. However, there is a clear discrepancy between the DD and MC simulations at bias voltages significantly exceeding the built-in potential when the LED consists of several deep quantum wells.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Charge transport, Drift-diffusion model, Hot carrier overflow, Light emitting diodes, Monte-Carlo transport
in
Advanced Electronic Materials
publisher
Wiley-VCH Verlag
external identifiers
  • scopus:85013276813
  • wos:000403287500010
DOI
10.1002/aelm.201600494
language
English
LU publication?
yes
id
01a35f2b-d8db-4a2c-9697-7ca33bad4c85
date added to LUP
2017-03-01 13:46:19
date last changed
2018-01-07 11:53:24
@article{01a35f2b-d8db-4a2c-9697-7ca33bad4c85,
  abstract     = {<p>Recent experiments have suggested that high energy charge carriers can have a significant effect on the operation of group III nitride (III-N) light-emitting diodes (LEDs), possibly playing an important role in the efficiency droop. As hot carriers are not accounted for by device simulation tools based on drift-diffusion (DD) and quasiequilibrium conditions, more advanced tools are needed. Here, fully self-consistent Monte Carlo (MC) simulations are developed to investigate the effects of hot carriers in device operation and to outline the shortcomings of the DD models in modeling multiquantum well (MQW) LEDs. The results show that hot carrier transport can lead to substantial electron overflow distributing the carriers more evenly in MQW structures, increasing the total recombination and leakage currents. Also Auger recombination is found to drive the distributions out of quasiequilibrium but, surprisingly, it does not contribute extensively to the leakage current. The simulations involve in-house ab-initio band structures as well as parameterized band structures, but qualitatively the results do not strongly depend on the band structure details. However, there is a clear discrepancy between the DD and MC simulations at bias voltages significantly exceeding the built-in potential when the LED consists of several deep quantum wells.</p>},
  author       = {Kivisaari, Pyry and Sadi, Toufik and Li, Jingrui and Rinke, Patrick and Oksanen, Jani},
  keyword      = {Charge transport,Drift-diffusion model,Hot carrier overflow,Light emitting diodes,Monte-Carlo transport},
  language     = {eng},
  month        = {02},
  publisher    = {Wiley-VCH Verlag},
  series       = {Advanced Electronic Materials},
  title        = {On the Monte Carlo Description of Hot Carrier Effects and Device Characteristics of III-N LEDs},
  url          = {http://dx.doi.org/10.1002/aelm.201600494},
  year         = {2017},
}