Multilayer solution-processed phosphorescent organic light-emitting diodes based on a crosslinkable and solvent-resistant hole transport material

Phosphorescent organic light-emitting diodes (PhOLEDs) with multiple functional layers are favorable for high device performance. However, due to the erosion between functional layers, it is still a great challenge to prepare multilayer devices with a low-cost solution process. In this manuscript, 4,4 '-bis (4-vinylphenyl) triphenylamine (VBTPA) can be in-situ polymerized as the thermally crosslinkable hole transport layer and successfully applied to solution-processed green light PhOLEDs by spin-coating method. It had the styryl groups as the thermally crosslinking position and can be crosslinked at 175 degrees C with short crosslinking time (20 min). The high thermal stability (446.0 degrees C), good photoelectric property and excellent solvent resistance and so forth, made the crosslinked VBTPA achieve a good device performance in solution-processed PhOLEDs. The turn-on voltage was 6.1 V, the maximum luminance was 8271 cd m(-2) and the maximum current efficiency was 12.4 cd A(-1). It indicated that the hole transport material with styryl groups as the thermally crosslinking position can be crosslinked under lower temperature (<200 degrees C) for shorter time and applied to the preparation of multilayer solution-processed stacked PhOLEDs.

Automated summary

This manuscript presents a low-cost solution process for preparing multilayer phosphorescent organic light-emitting diodes (PhOLEDs). By in-situ polymerization of a thermally crosslinkable hole transport layer, the resulting device demonstrates excellent performance.