Spray deposition of organic electroluminescent coatings for application in flexible light emitting devices

Cogent Engineering

Mariya Aleksandrova¹  Georgi Kolev¹  Svetozar Andreev¹ 

[1] Technical University of Sofia;

关键词: spray deposition;    organic coatings;    flexible displays;    electroluminescence;    thin films;   

DOI  :  10.1080/23311916.2015.1014248

来源: DOAJ

【 摘 要 】

Organic electroluminescent (EL) films of tris(8-hydroxyquinolinato)aluminum (Alq3) mixed with polystyrene (PS) binder were produced by spray deposition. The influence of the substrate temperature on the layer’s morphology and uniformity was investigated. The deposition conditions were optimized and simple flexible light-emitting devices consisting of indium-tin oxide/Alq3:PS/aluminum were fabricated on polyethylene terephthalate (PET) foil to demonstrate the advantages of the sprayed organic coatings. Same structure was produced by thermal evaporation of Alq3 film as a reference. The influence of the deposition method on the film roughness and contact resistance at the electrode interfaces for both types of structures was estimated. The results were related to the devices’ efficiency. It was found that the samples with sprayed films turn on at 4 V, which is 2 V lower in comparison to the device with thermal evaporated Alq3. The current through the sprayed device is six times higher as well (17 mA vs. 2.8 mA at 6.5 V), which can be ascribed to the lower contact resistance at the EL film/electrode interfaces. This is due to the lower surface roughness of the pulverized layers.

【 授权许可】

Unknown