Highly Air-Stable Electron-Transport Material for Ink-Jet-Printed OLEDs

A novel cross‐linkable electron‐transport material has been designed and synthesized for use in the fabrication of solution‐processed OLEDs. The material exhibits a low LUMO level of −3.51 eV, a high electron mobility of 1.5×10−5 cm2 V−1 s−1, and excellent stability. An average 9.3 % shrinkage in film thickness was observed for the film after thermal curing. A maximum external quantum efficiency (EQE) of 15.6 % (35.0 cd A−1) was achieved for blue‐phosphorescent OLEDs by spin‐coating and 13.8 % (31.0 cd A−1) for an ink‐jet‐printed device, both of which are better than the EQE of a control device prepared by vacuum‐deposition (see figure). Efficient OLEDs: A novel cross‐linkable electron‐transport material has been synthesized for use in solution‐processed OLEDs. A maximum external quantum efficiency (EQE) of 15.6 % (35.0 cd A−1) was achieved for blue‐phosphorescent OLEDs by spin‐coating and 13.8 % (31.0 cd A−1) for an ink‐jet‐printed device, both of which are better than the EQE of a control device prepared by vacuum‐deposition (see figure).