Inkjet printing high luminance phosphorescent OLED based on m-MTDATA:TPBi host

In organic light-emitting devices (OLEDs), the high performance of devices depends on balanced charge transfer in emitting layer (EML). However, the balance charge transfer is hard to achieve in the single host material-based EML. In this work, a high luminance co-host based OLEDs is printed. In detail, green phosphorescent material tris[2-(p-tolyl)pyridine]iridium(III) [Formula: see text] is used as dopant, and a hole-transporting material [Formula: see text]-tris[3-methy-lphenyl(phenyl)amino]-triphenylamine (m-MTDATA) blended with an electron-transporting material 1,3,5-tris(phenyl-2-benzimidazolyl)-benzene (TPBi) as co-host. As a result, the optimized printing co-host OLEDs with 10 wt.% [Formula: see text] shows a maximum luminance of [Formula: see text], which is much higher than the CDBP counterpart.