Droop and light extraction of InGaN-based red micro-light-emitting diodes

Jeong Hwan Park, Markus Pristovsek, Cai Wentao, Takeru Kumabe, Soo Young Choi, Dong Seon Lee, Tae Yeon Seong, Hiroshi Amano

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


In this letter, we investigate the impact of periphery, width, length and area on the external quantum efficiency (EQE) of stripe-type InGaN-based red micro-light-emitting diodes (µLEDs). A longer periphery resulted in a higher light extraction efficiency ( η e ) via the sidewall regardless of the area of the µLEDs. However, as the injection current increased a somewhat larger efficiency droop was observed at the longer periphery due to current crowding. Additionally, larger µLEDs experienced more self-heating than smaller ones, resulting in a red shift of wavelengths and a larger efficiency droop. When the current density exceeded 100 A cm−2, the EQE ratio of smaller-area μLEDs to larger-area ones increased significantly due to the difference in efficiency droop. Besides, a short light propagation length and a long emission width yielded a higher η e . Hence, the periphery, width, length and area of the µLEDs determine EQE, which provides insight into the pixel design of µLED displays.

Original languageEnglish
Article number01LT01
JournalSemiconductor Science and Technology
Issue number1
Publication statusPublished - 2024 Jan

Bibliographical note

Publisher Copyright:
© 2023 IOP Publishing Ltd.


  • InGaN red
  • efficiency droop
  • external quantum efficiency
  • light extraction efficiency
  • micro-LEDs

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


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