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

Journal Article · Wed Oct 15 00:00:00 EDT 2014 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.04.063· OSTI ID:22420582

Lee, Kwanjae; Lee, Hyunjung; Lee, Cheul-Ro ^[1]; Lee, Jin Hong ^[2]; Ryu, Mee-Yi ^[3]; Leem, Jae-Young ^[4]

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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)

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.

• OSTI ID: 22420582
• Journal Information: Materials Research Bulletin, Vol. 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); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

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