Direct measurement of electric field screening in light emitting diodes with conjugated polyelectrolyte electron injecting/transport layers
Electroabsorption spectroscopy was used to directly probe the electric fields in a polymer light emitting diode that utilizes a conjugated polyelectrolyte electron transporting/injection layer. The electric field in the emitting layer was found to be negligible at applied biases greater than the bui...
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Veröffentlicht in: | Applied physics letters 2009-01, Vol.94 (3) |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | Electroabsorption spectroscopy was used to directly probe the electric fields in a polymer light emitting diode that utilizes a conjugated polyelectrolyte electron transporting/injection layer. The electric field in the emitting layer was found to be negligible at applied biases greater than the built-in field of the device. Holes injected at these biases accumulate at the emitting layer/conjugated polyelectrolyte interface and screen the field from the emitting layer to the conjugated polyelectrolyte layer. In conjunction with mobile ions that redistribute the field in the conjugated polyelectrolyte layer, this leads to greatly improved electron injection from high work function cathodes. |
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ISSN: | 0003-6951 1077-3118 |
DOI: | 10.1063/1.3069279 |