InGaN/GaN LEDs optical output efficiency enhancement based on AFM surface morphology studies of the constituent layers
For GaN‐based light emitting diodes (LEDs), the growth mechanism and interface roughness of the n‐contact, active region, and p‐contact layers are of vital importance for achieving superior optical and electrical characteristics of such devices. Nanoscale range surface morphology is one of the key p...
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Published in | Physica status solidi. C Vol. 2; no. 7; pp. 2882 - 2886 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
01.05.2005
WILEY‐VCH Verlag |
Subjects | |
Online Access | Get full text |
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Summary: | For GaN‐based light emitting diodes (LEDs), the growth mechanism and interface roughness of the n‐contact, active region, and p‐contact layers are of vital importance for achieving superior optical and electrical characteristics of such devices. Nanoscale range surface morphology is one of the key parameters actively employed to developing high optical efficiency applications. In this study, we illustrate the use of atomic force microscopy to investigate and optimise the surface morphology of (a) sapphire substrates and (b) metalorganic chemical vapour deposition (MOCVD) grown InGaN/GaN LED constituent layers (i.e., n‐GaN, InGaN active region, and p‐GaN). Several optimal cases are presented and discussed, where based on the surface morphology findings an improved selection of (a) substrates and (b) MOCVD growth parameters was achieved leading to an overall enhancement (over 2 times) of the optical output efficiency of these devices. Applying the principles and observations reported, a thermally robust 465 nm multiple quantum well LED with an unpackaged chip‐level power output in the 4.0–5.0 mW range and forward voltage <3.2 V at 20 mA was consistently achieved. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
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Bibliography: | istex:B5AF64C1FDCD14819FAEB82E78A0210F6DB94912 ArticleID:PSSC200461357 ark:/67375/WNG-2GKNJDL0-K ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1610-1634 1610-1642 |
DOI: | 10.1002/pssc.200461357 |