The Study of In Clustering Effects in InGaN/GaN Multiple Quantum Well Structure

InGaN/GaN 다중 양자우물 구조에서의 In 응집 현상의 연구

  • 조형균 (한국과학기술원 재료공학과) ;
  • 이정용 (한국과학기술원 재료공학과) ;
  • 김치선 (전북대학교 반도체과학기술학과) ;
  • 양계모 (전북대학교 반도체과학기술학과)
  • Published : 2001.07.01

Abstract

InGaN/GaN multiple quantum wells (MQWs) grown with various growth interruptions between the InGaN well and GaN barrier by metal-organic chemical vapor deposition were investigated using photoluminescence, high-resolution transmission electron microscopy, and energy filtered transmission electron microscopy (EFTEM). The luminescence intensity of the MQWs with growth interruptions is abruptly reduced compared to that of the MQW without growth interruption. Also, as the interruption time increases the peak emission shows a continuous blue shift. Evidence of indium clustering is directly observed both by using an indium ratio map of the MQWs and from indium composition measurements along an InGaN well using EFTEM. The higher intensity and lower energy emission of light from the MQW grown without interruption showing indium clustering is believed to be caused by the recombination of excitons localized in indium clustering regions and the increased indium composition in these recombination centers.

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