Generated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diode

Handle URI:
http://hdl.handle.net/10754/626441
Title:
Generated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diode
Authors:
Ajia, Idris A. ( 0000-0003-3156-4426 ) ; Edwards, Paul R.; Pak, Yusin; Belekov, Ermek.; Roldan, Manuel A; Wei, Nini; Liu, Zhiqiang; Martin, Robert W.; Roqan, Iman S. ( 0000-0001-7442-4330 )
Abstract:
We investigate the effects of V-pits on the optical properties of a state-of-the art highly efficient, blue InGaN/GaN multi-quantum-well (MQW) light emitting diode (LED) with high internal quantum efficiency (IQE) of > 80%. The LED is structurally enhanced by incorporating pre-MQW InGaN strain-relief layer with low InN content and patterned sapphire substrate. For comparison, a conventional (unenhanced) InGaN/GaN MQW LED (with IQE of 46%) grown under similar conditions was subjected to the same measurements. Scanning transmission electron microscopy (STEM) reveals the absence of V-pits in the unenhanced LED, whereas in the enhanced LED, V-pits with {10-11} facets, emerging from threading dislocations (TDs) were prominent. Cathodoluminescence mapping reveals the luminescence properties near the V-pits, showing that the formation of V-pit defects can encourage the growth of defect-neutralizing barriers around TD defect states. The diminished contribution of TDs in the MQWs allows indium-rich localization sites to act as efficient recombination centers. Photoluminescence and time-resolved spectroscopy measurements suggest that the V-pits play a significant role in the generated carrier rate and droop mechanism, showing that the quantum confined Stark effect is suppressed at low generated carrier density, after which the carrier dynamics and droop are governed by the carrier overflow effect.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Imaging and Characterization Core Lab
Citation:
Ajia IA, Edwards PR, Pak Y, Belekov E, Roldan MA, et al. (2017) Generated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diode. ACS Photonics. Available: http://dx.doi.org/10.1021/acsphotonics.7b00944.
Publisher:
American Chemical Society (ACS)
Journal:
ACS Photonics
Issue Date:
18-Dec-2017
DOI:
10.1021/acsphotonics.7b00944
Type:
Article
ISSN:
2330-4022; 2330-4022
Sponsors:
The authors thank King Abdullah University of Science and Technology for the financial support.
Additional Links:
http://pubs.acs.org/doi/10.1021/acsphotonics.7b00944
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorAjia, Idris A.en
dc.contributor.authorEdwards, Paul R.en
dc.contributor.authorPak, Yusinen
dc.contributor.authorBelekov, Ermek.en
dc.contributor.authorRoldan, Manuel Aen
dc.contributor.authorWei, Ninien
dc.contributor.authorLiu, Zhiqiangen
dc.contributor.authorMartin, Robert W.en
dc.contributor.authorRoqan, Iman S.en
dc.date.accessioned2017-12-27T13:11:15Z-
dc.date.available2017-12-27T13:11:15Z-
dc.date.issued2017-12-18en
dc.identifier.citationAjia IA, Edwards PR, Pak Y, Belekov E, Roldan MA, et al. (2017) Generated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diode. ACS Photonics. Available: http://dx.doi.org/10.1021/acsphotonics.7b00944.en
dc.identifier.issn2330-4022en
dc.identifier.issn2330-4022en
dc.identifier.doi10.1021/acsphotonics.7b00944en
dc.identifier.urihttp://hdl.handle.net/10754/626441-
dc.description.abstractWe investigate the effects of V-pits on the optical properties of a state-of-the art highly efficient, blue InGaN/GaN multi-quantum-well (MQW) light emitting diode (LED) with high internal quantum efficiency (IQE) of > 80%. The LED is structurally enhanced by incorporating pre-MQW InGaN strain-relief layer with low InN content and patterned sapphire substrate. For comparison, a conventional (unenhanced) InGaN/GaN MQW LED (with IQE of 46%) grown under similar conditions was subjected to the same measurements. Scanning transmission electron microscopy (STEM) reveals the absence of V-pits in the unenhanced LED, whereas in the enhanced LED, V-pits with {10-11} facets, emerging from threading dislocations (TDs) were prominent. Cathodoluminescence mapping reveals the luminescence properties near the V-pits, showing that the formation of V-pit defects can encourage the growth of defect-neutralizing barriers around TD defect states. The diminished contribution of TDs in the MQWs allows indium-rich localization sites to act as efficient recombination centers. Photoluminescence and time-resolved spectroscopy measurements suggest that the V-pits play a significant role in the generated carrier rate and droop mechanism, showing that the quantum confined Stark effect is suppressed at low generated carrier density, after which the carrier dynamics and droop are governed by the carrier overflow effect.en
dc.description.sponsorshipThe authors thank King Abdullah University of Science and Technology for the financial support.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/10.1021/acsphotonics.7b00944en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/10.1021/acsphotonics.7b00944.en
dc.subjectInGaNen
dc.subjectefficiency droopen
dc.subjectlight emitting diodeen
dc.subjectcarrier dynamicsen
dc.subjecttime-resolved spectroscopyen
dc.titleGenerated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diodeen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentImaging and Characterization Core Laben
dc.identifier.journalACS Photonicsen
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom.en
dc.contributor.institutionDevelopment Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China.en
kaust.authorAjia, Idris A.en
kaust.authorPak, Yusinen
kaust.authorBelekov, Ermek.en
kaust.authorRoldan, Manuel Aen
kaust.authorWei, Ninien
kaust.authorRoqan, Iman S.en
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