Abstract
The operating lifetimes of light-emitting diode structures incorporating poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) Langmuir-Blodgett films are reported. To remove the moisture from the organic layer, a number of post-deposition treatments have been investigated prior to the deposition of the metal top contact. The best external quantum efficiency was found for an indium-tin oxide/MEH-PPV/aluminium structure dried in high vacuum. However, this device possessed a relatively short lifetime. Experiments at constant current and constant voltage revealed that annealing at an elevated temperature could enhance the lifetime. Further improvements were found for devices in which a lithium fluoride layer (approximate to 2 nm) was sandwiched between the aluminium electrode and the polymer layer, and by encapsulating the device with adhesive tape. (C) 2001 Elsevier Science B.V. All rights reserved.
| Original language | English |
|---|---|
| Number of pages | 1 |
| Volume | 14 |
| Publication status | Published - 15 Aug 2001 |
Keywords
- light-emitting diode
- Langmuir-Blodgett film
- MEH-PPV
- ORGANIC ELECTROLUMINESCENT DEVICES
- CONJUGATED POLYMERS
- INTERCHAIN INTERACTIONS
- THIN-FILMS
- DEGRADATION
- LUMINESCENCE
- STABILITY
- PERFORMANCE
- EFFICIENCY