Effect of internal electrostatic fields in InGaN quantum wells on the properties of green light emitting diodes

Z. H. Wu, A. M. Fischer, Fernando Ponce, W. Lee, J. H. Ryou, J. Limb, D. Yoo, R. D. Dupuis

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Variations in the strength of the piezoelectric field inside InGaN quantum wells have been observed along the growth direction in InGaN-based diodes emitting light in the green region. The internal electrostatic potential distribution across the active region consisting of five InGaN quantum wells has been determined by electron holography in a transmission electron microscope. The strength of the piezoelectric field decreases in the direction towards the p-n junction. Its effect on light emission has been evaluated by depth-profiling cathodoluminescence, where the emission from two peaks becomes increasingly distinct with increasing excitation voltage. The drop in piezoelectric field strength is proposed to be related to the neutralization of piezoelectric charges by hydrogen ions which are initially abundant in the p region and diffuse into the quantum wells during thermal annealing.

Original languageEnglish (US)
Article number041915
JournalApplied Physics Letters
Volume91
Issue number4
DOIs
StatePublished - 2007

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light emitting diodes
quantum wells
electric fields
hydrogen ions
cathodoluminescence
p-n junctions
holography
light emission
field strength
electron microscopes
electrostatics
annealing
electric potential
excitation
electrons

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Effect of internal electrostatic fields in InGaN quantum wells on the properties of green light emitting diodes. / Wu, Z. H.; Fischer, A. M.; Ponce, Fernando; Lee, W.; Ryou, J. H.; Limb, J.; Yoo, D.; Dupuis, R. D.

In: Applied Physics Letters, Vol. 91, No. 4, 041915, 2007.

Research output: Contribution to journalArticle

Wu, Z. H. ; Fischer, A. M. ; Ponce, Fernando ; Lee, W. ; Ryou, J. H. ; Limb, J. ; Yoo, D. ; Dupuis, R. D. / Effect of internal electrostatic fields in InGaN quantum wells on the properties of green light emitting diodes. In: Applied Physics Letters. 2007 ; Vol. 91, No. 4.
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