Electroluminescence and Photophysical Properties of Polyquinolines
Abstract
The electroluminescence and photophysical properties of a series of eleven polyquinolines were investigated and used to explore the effects of molecular and supramolecular structures on the light-emitting properties of polymers. Thin films of the polyquinolines have photoluminescence quantum yields between 2 and 30% and unusually long excited state lifetimes of 2.4 to 5.2 ns. Electroluminescence colors spanning blue, green, yellow, orange, and red were obtained through regulation of the molecular and supramolecular structures of the excimer- and aggregate-forming polyquinolines. ITO/hole transport layer/polyquinoline/Al light-emitting diodes fabricated and evaluated in air had electroluminescence quantum efficiencies between 0.02 and 1% and luminance levels of up to 280 cd/sq m at a current density of 100 mA/sq cm. The electroluminescence efficiency approximately scaled linearly with the photoluminescence quantum yield. Favorable reaction at the aluminum/polyquinoline interface is proposed to account for the efficient election injection and device performance in spite of the large (1.5-1.9 eV) energetic barrier to electron injection. These results provide new insights into the design of efficient light-emitting polymer materials and devices for optoelectronic applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 16, 1999
- Accession Number
- ADA366991
Entities
People
- Ashok S. Shetty
- Samson A. Jenekhe
- Xuejun Zhang
Organizations
- University of Rochester