Abstract
The relationship between the thermal evaporation rate of Al cathodes and the device performance of organic light-emitting diodes (OLEDs) was investigated to clarify the source of leakage current. Time-of-flight secondary ion mass spectrometry was applied to identify the diffusion of Li and Al fragments into the underlying organic layer during the thermal evaporation process. We prepared various OLEDs by varying the evaporation rates of the Al cathode to investigate different device performance. Interestingly, the leakage current level decreased when the evaporation rate reached ∼25 Å/s. In contrast, the best efficiency and operational lifetime was obtained when the evaporation rate was 5 Å/s.
| Original language | English |
|---|---|
| Pages (from-to) | 8-12 |
| Number of pages | 5 |
| Journal | Materials Science and Engineering B: Solid-State Materials for Advanced Technology |
| Volume | 188 |
| DOIs | |
| Publication status | Published - Oct 2014 |
Bibliographical note
Funding Information:This work was supported by the National Research Foundation of Korea (NRF) funded by the Korea government (MSIP) (No. 2014R1A2A2A01002417) and the Industrial Strategic Technology Development Program (Grant No. 10042590 ) funded by the Ministry of Knowledge Economy (MKE, Korea). This work was also supported by the Human Resources Development Program (No. 20134010200490 ) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Government Ministry of Trade, Industry and Energy .
Keywords
- Evaporation rate
- High efficiency
- Leakage current
- Lifetime
- OLED