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Title: Spatial emission distribution of InGaN/GaN light-emitting diodes depending on the pattern structures

Highlights: • We study carrier lifetimes of InGaN/GaN LEDs fabricated on different PSS. • Spatial EL distribution was investigated depending on the pattern structure. • The carrier lifetime of the LEDs was compared with the spatial EL distribution. - Abstract: We investigated the emission characteristics of InGaN/GaN light-emitting diodes (LEDs) fabricated on lens-shaped (LS) patterned-sapphire substrates (PSS) by using time-resolved photoluminescence (TRPL) and confocal-scanning-electroluminescence microscopy (CSEM). The carrier lifetimes evaluated from the TRPL spectra for the LEDs on the LS-PSS (LS-LEDs) at 10 K were relatively shorter than those of the LEDs on a conventional planar substrate (C-LED). However, the carrier lifetimes for the LS-LEDs were relatively long compared to that of the C-LED at room temperature. In the CSEM images of the LS-LEDs, the emission beam around the center region of the LS pattern was relatively weaker than that of the edge region. In addition, the beam profile for the LS-LEDs showed different shapes according to the pattern structures. The emission beam around the boundary region of the LS pattern showed periodic fluctuation with the peak-to-peak distance of 814 nm.
Authors:
; ;  [1] ;  [1] ;  [2] ;  [3] ;  [4]
  1. Division of Advanced Materials Engineering, Research Center of Advanced Materials Development, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)
  2. Korea Photonics Technology Institute, Gwangju 500-779 (Korea, Republic of)
  3. Department of Physics, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)
  4. School of Nano Engineering, Inje University, Gimhae 621-749 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22420582
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 58; Conference: IFFM2013: International forum on functional materials, Jeju City (Korea, Republic of), 27-29 Jun 2013; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARRIER LIFETIME; COMPARATIVE EVALUATIONS; ELECTROLUMINESCENCE; EMISSION SPECTROSCOPY; EPITAXY; FLUCTUATIONS; GALLIUM NITRIDES; INDIUM COMPOUNDS; LIGHT EMITTING DIODES; MICROSCOPY; OPTICAL PROPERTIES; PHOTOLUMINESCENCE; SAPPHIRE; SEMICONDUCTOR MATERIALS; SUBSTRATES; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; TIME RESOLUTION