Solution-Processed Organic Light-Emitting Diodes With Slot-Die Coated Electron Transport Layer

To fabricate fully solution-processed small-molecule organic light-emitting diodes (OLEDs), we investigate the slot-die coating technique for the small-molecule electron transport layer (ETL). 2,2’,2”-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) was dissolved in methanol and slot-die coated as ETL and applied in multilayer OLEDs with small-molecule Bis(4-phenylthieno[3,2-c]pyridinato-N, C2’) (acetylacetonate) iridium(III) (PO-01) doped in 4,4’-Bis(carbazol-9-yl)biphenyl (CBP) host as an emissive layer. The ETL provides efficient electron injection and electron transport ability in the devices. The efficiency of the devices with the combination of ETL and Ca/Al cathode reaches 0.8 cd/A at 1000 cd/m
²
.