Improvement of ultra-deep ultraviolet light emitting diodes with asymmetric active region

Man Fang Huang, Tsung Hung Lu

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We have theoretically investigated the optimized quantum well structure for the ultra-deep ultraviolet (UV) AlGaN light emitting diodes (LEDs) with the consideration of band structure deformation caused by polarization effect. In this paper, we further employ an asymmetric active region to reduce the polarization field in the well-barrier interface and modify the band structure to enhance the power efficiency of the AlGaN LED. By increasing the thickness of p-side barrier from 5 nm to 15 nm, the deformation slope of energy band in the well region is reduced due to the reduction of polarization field, which is caused by the large polarization charges in the interface of p-side barrier and carrier blocking layer. Accordingly, the hole concentration is increased and the carrier distributions are more uniform caused by the less-tilted energy band in the well. Therefore, a higher recombination rate and a higher output power can be obtained. Moreover, the power efficiency of AlGaN LED is barely related to the n-side barrier thickness due to the less polarization field. However, a thinner n-side barrier is preferred to enhance the current spreading. Therefore, an asymmetric QW with a thinner n-side barrier and a thicker p-side barrier is a better choice to enhance the power efficiency for the deep UV AlGaN LED.

Original languageEnglish
Title of host publicationLight-Emitting Diodes
Subtitle of host publicationResearch, Manufacturing, and Applications X
Publication statusPublished - 2006 May 26
EventLight-Emitting Diodes: Research, Manufacturing, and Applications X - San Jose, CA, United States
Duration: 2006 Jan 252006 Jan 26

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherLight-Emitting Diodes: Research, Manufacturing, and Applications X
CountryUnited States
CitySan Jose, CA

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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