hig.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Surface energy modification of metal oxide to enhance electron injection in light-emitting devices: charge balance in hybrid OLEDs and OLETs
University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
2017 (English)Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
Abstract [en]

Organic semiconductors (OSCs) present an electron mobility lower by several orders of magnitude than the hole mobility, giving rise to an electron-hole charge imbalance in organic devices such as organic light-emitting diodes (OLEDs) and organic light-emitting transistors (OLETs). In this thesis project, I tried to achieve an efficient electron transport and injection properties in opto-electronic devices, using inorganic n-type metal oxides (MOs) instead of organic n-type materials and a polyethyleneimine ethoxylated (PEIE) thin layer as electron transport (ETLs) and injection layers (EILs), respectively. In the first part of this thesis, inverted OLEDs were fabricated in order to study the effect of the PEIE layer in-between ZnO and two different emissive layers (EMLs): poly(9,9-dioctylfluorene-alt-benzothiadiazole) polymer (F8BT) and tris(8-hydroxyquinolinato) aluminum small molecule (Alq3), based on a solution and thermal evaporation processes, respectively. Different concentrations (0.80 %, 0.40 %) of PEIE layers were used to further study electron injection capability in OLEDs. After a series of optimizations in the fabrication process, the opto-electrical characterization showed high-performance of devices. The inverted OLEDs reported a maximum luminance over 104 cd m-2 and a maximum external quantum efficiency (EQE) around 1.11 %. The results were attributed to the additional PEIE layer which provided a good electron injection from MOs into EMLs. In the last part of the thesis, OLETs were fabricated and discussed by directly transferring the energy modification layer from OLEDs to OLETs. As metal oxide layer, ZnO:N was employed for OLETs since ZnO:N-based thin film transistors (TFTs) showed better performance than ZnO-based TFTs. Finally, due to their short life-time, OLETs were characterized electrically but not optically.

Place, publisher, year, edition, pages
2017. , 73 p.
Keyword [en]
organic, inorganic, semiconductors, OLEDs, OLETs, TFT, stack, thin-film, deposition, spin-coating, thermal, evaporation, process, reactive, sputtering, luminescence, EQE, PEIE, metal-oxide, ZnO, ZnO:N, MoO3, F8BT, Alq3, NPB
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:hig:diva-25097OAI: oai:DiVA.org:hig-25097DiVA: diva2:1135853
External cooperation
IMEC
Subject / course
Electronics
Educational program
Electronics/Telecommunications – master’s programme (two years) (swe or eng)
Supervisors
Examiners
Available from: 2017-09-04 Created: 2017-08-24 Last updated: 2017-09-04Bibliographically approved

Open Access in DiVA

fulltext(5299 kB)50 downloads
File information
File name FULLTEXT01.pdfFile size 5299 kBChecksum SHA-512
999bace95af23918eb86985658002c936bbf0338d228d3fb7491e08d1fcea7e149a70a9ef771357920375d3cb8b4ceeecad528f4d2426462801af56ab5b9a5e2
Type fulltextMimetype application/pdf

By organisation
Department of Electronics, Mathematics and Natural Sciences
Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 50 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 167 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf