Effect of injection layer sub-bandgap states on electron injection in organic light-emitting diodes
It is generally considered that the injection of charges into an active layer of an organic light-emitting diode (OLED) is solely determined by the energetic injection barrier formed at the device interfaces. Here, we demonstrate that the density of surface states of the electron-injecting ZnO layer...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 18, 2017
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| In: |
ACS applied materials & interfaces
Year: 2017, Volume: 9, Issue: 7, Pages: 6220-6227 |
| ISSN: | 1944-8252 |
| DOI: | 10.1021/acsami.6b14594 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1021/acsami.6b14594 Verlag, Volltext: https://doi.org/10.1021/acsami.6b14594 
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| Author Notes: | Carsten Hinzmann, Osnat Magen, Yvonne J. Hofstetter, Paul E. Hopkinson, Nir Tessler, and Yana Vaynzof |
| Summary: | It is generally considered that the injection of charges into an active layer of an organic light-emitting diode (OLED) is solely determined by the energetic injection barrier formed at the device interfaces. Here, we demonstrate that the density of surface states of the electron-injecting ZnO layer has a profound effect on both the charge injection and the overall performance of the OLED device. Introducing a dopant into ZnO reduces both the energy depth and density of surface states without altering the position of the energy levels - thus, the magnitude of the injection barrier formed at the organic/ZnO interface remains unchanged. Changes observed in the density of surface states result in an improved electron injection and enhanced luminescence of the device. We implemented a numerical simulation, modeling the effects of energetics and the density of surface states on the electron injection, demonstrating that both contributions should be considered when choosing the appropriate injection layer. |
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| Item Description: | Gesehen am 10.07.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1944-8252 |
| DOI: | 10.1021/acsami.6b14594 |