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Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence

Pozina, Galia ; Ciechonski, Rafal ; Bi, Zhaoxia LU orcid ; Samuelson, Lars LU and Monemar, Bo LU (2015) In Applied Physics Letters 107(25).
Abstract

Today's energy saving solutions for general illumination rely on efficient white light emitting diodes (LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show using cathodoluminescence (CL) spatial mapping at different electron beam currents that threading dislocations are active as nonradiative recombination centers only at high injection conditions. At low current, the dislocations are inactive in carrier recombination due to local potentials, but these potentials are screened by carriers at higher injection levels. In CL images, this corresponds to the increase of the dark contrast around... (More)

Today's energy saving solutions for general illumination rely on efficient white light emitting diodes (LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show using cathodoluminescence (CL) spatial mapping at different electron beam currents that threading dislocations are active as nonradiative recombination centers only at high injection conditions. At low current, the dislocations are inactive in carrier recombination due to local potentials, but these potentials are screened by carriers at higher injection levels. In CL images, this corresponds to the increase of the dark contrast around dislocations with the injection (excitation) density and can be linked with droop related to the threading dislocations. Our data indicate that reduction of droop in the future efficient white LED can be achieved via a drastic reduction of the dislocation density by using, for example, bulk native substrates.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied Physics Letters
volume
107
issue
25
article number
251106
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:84952701093
ISSN
0003-6951
DOI
10.1063/1.4938208
language
English
LU publication?
yes
id
805a9dac-fcd7-46b2-909e-53c63b90e177
date added to LUP
2019-05-10 13:52:28
date last changed
2022-01-31 19:45:01
@article{805a9dac-fcd7-46b2-909e-53c63b90e177,
  abstract     = {{<p>Today's energy saving solutions for general illumination rely on efficient white light emitting diodes (LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show using cathodoluminescence (CL) spatial mapping at different electron beam currents that threading dislocations are active as nonradiative recombination centers only at high injection conditions. At low current, the dislocations are inactive in carrier recombination due to local potentials, but these potentials are screened by carriers at higher injection levels. In CL images, this corresponds to the increase of the dark contrast around dislocations with the injection (excitation) density and can be linked with droop related to the threading dislocations. Our data indicate that reduction of droop in the future efficient white LED can be achieved via a drastic reduction of the dislocation density by using, for example, bulk native substrates.</p>}},
  author       = {{Pozina, Galia and Ciechonski, Rafal and Bi, Zhaoxia and Samuelson, Lars and Monemar, Bo}},
  issn         = {{0003-6951}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{25}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Applied Physics Letters}},
  title        = {{Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence}},
  url          = {{http://dx.doi.org/10.1063/1.4938208}},
  doi          = {{10.1063/1.4938208}},
  volume       = {{107}},
  year         = {{2015}},
}