Improving output power performance of InGaN-based light-emitting diodes by employing step-down indium contents

Daesung Kang, Taejoon Kim, Kiyoung Song, Jihyun Back, Hwanhee Jeong, June O. Song, Tae Yeon Seong

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6 Citations (Scopus)

Abstract

We investigated the effect of step-down indium content in InGaN quantum wells (QWs) on the output efficiency of fully packaged InGaN-based light-emitting diodes (LEDs). Both the reference and step-down LED chips give maximum external quantum efficiencies (EQE) of 54.65 and 54.99% at a current density of 4.17A/cm2, respectively. Step-down LEDs show a lower efficiency droop than reference LEDs. The step-down LEDs exhibit a 5.3% higher EQE at 83.3 A/cm2 than the reference LEDs. As the current density increases from 1.39 to 9.03A/cm2, the electroluminescence (EL) intensity peaks of the step-down LEDs are slightly more shifted towards the larger energy side than those of the reference LEDs. The polarization field is estimated to be 1.34 and 1.41MV /cm for the reference and step-down LEDS, respectively. The simulated internal quantum efficiency results of the reference and step-down LEDs are in agreement with the experimental results. The simulation results show that the step-down LEDs have higher hole injection efficiency than the reference LEDs. On the basis of the simulation results, the blue-shift behavior of the reference and step-down LEDs is described and discussed.

Original languageEnglish
Article number042102
JournalJapanese Journal of Applied Physics
Volume54
Issue number4
DOIs
Publication statusPublished - 2015 Apr 1

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ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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