hh.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Optimization of Current Injection in AlGaInP Core−Shell Nanowire Light-Emitting Diodes
Solid State Physics and NanoLund, Lund University, Lund, Sweden.ORCID-id: 0000-0001-8434-3438
Solid State Physics and NanoLund, Lund University, Lund, Sweden.
Solid State Physics and NanoLund, Lund University, Lund, Sweden.ORCID-id: 0000-0002-3160-8540
Solid State Physics and NanoLund, Lund University, Lund, Sweden.
Visa övriga samt affilieringar
2017 (Engelska)Ingår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 17, nr 6, s. 3599-3606Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Core–shell nanowires offer great potential to enhance the efficiency of light-emitting diodes (LEDs) and expand the attainable wavelength range of LEDs over the whole visible spectrum. Additionally, nanowire (NW) LEDs can offer both improved light extraction and emission enhancement if the diameter of the wires is not larger than half the emission wavelength (λ/2). However, AlGaInP nanowire LEDs have so far failed to match the high efficiencies of traditional planar technologies, and the parameters limiting the efficiency remain unidentified. In this work, we show by experimental and theoretical studies that the small nanowire dimensions required for efficient light extraction and emission enhancement facilitate significant loss currents, which result in a low efficiency in radial NW LEDs in particular. To this end, we fabricate AlGaInP core–shell nanowire LEDs where the nanowire diameter is roughly equal to λ/2, and we find that both a large loss current and a large contact resistance are present in the samples. To investigate the significant loss current observed in the experiments in more detail, we carry out device simulations accounting for the full 3D nanowire geometry. According to the simulations, the low efficiency of radial AlGaInP nanowire LEDs can be explained by a substantial hole leakage to the outer barrier layer due to the small layer thicknesses and the close proximity of the shell contact. Using further simulations, we propose modifications to the epitaxial structure to eliminate such leakage currents and to increase the efficiency to near unity without sacrificing the λ/2 upper limit of the nanowire diameter. To gain a better insight of the device physics, we introduce an optical output measurement technique to estimate an ideality factor that is only dependent on the quasi-Fermi level separation in the LED. The results show ideality factors in the range of 1–2 around the maximum LED efficiency even in the presence of a very large voltage loss, indicating that the technique is especially attractive for measuring nanowire LEDs at an early stage of development before electrical contacts have been optimized. The presented results and characterization techniques form a basis of how to simultaneously optimize the electrical and optical efficiency of core–shell nanowire LEDs, paving the way to nanowire light emitters that make true use of larger-than-unity Purcell factors and the consequently enhanced spontaneous emission. © 2017American Chemical Society

Ort, förlag, år, upplaga, sidor
American Chemical Society (ACS), 2017. Vol. 17, nr 6, s. 3599-3606
Nationell ämneskategori
Nanoteknik
Identifikatorer
URN: urn:nbn:se:hh:diva-34048DOI: 10.1021/acs.nanolett.7b00759ISI: 000403631600041PubMedID: 28535346Scopus ID: 2-s2.0-85020753897OAI: oai:DiVA.org:hh-34048DiVA, id: diva2:1107772
Tillgänglig från: 2017-06-10 Skapad: 2017-06-10 Senast uppdaterad: 2018-04-03Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextPubMedScopus

Personposter BETA

Kivisaari, PyryKarimi, MohammadLimpert, StevenPettersson, HåkanBorgström, Magnus T.

Sök vidare i DiVA

Av författaren/redaktören
Kivisaari, PyryKarimi, MohammadLimpert, StevenPettersson, HåkanBorgström, Magnus T.
Av organisationen
Tillämpad matematik och fysik (MPE-lab)
I samma tidskrift
Nano letters (Print)
Nanoteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetricpoäng

doi
pubmed
urn-nbn
Totalt: 135 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf