Here, a new series of crosslinkable heteroieptic iridium (III) complexes for use in solution processed phosphorescent organic light emitting diodes (OLEDs) is reported. These iridium compounds have the general formula of (PPZVB) 2lr(ĈN), where PPZ-VB is phenylpyrazoie (PPZ) vinyi benzyl (VB) ether; and the ĈN ligands represent a family of four different cyclometaliating ligands including 1-pheuylpyrazolyl (PPZ) (1), 2-(4,6-difluorophenyl)pyridyl (DFPPY) (2), 2-(p-tolyl)pyridyl (TPY) (3), and 2-phenylquinolyl (PQ) (4). With the incorporation of two crosslinkable VB ether groups, these compounds can be fully crosslinked after heating at 180 °C for 30 min. The crosslinked films exhibit excellent solvent resistance and film smoothness which enables fabrication of high-performance multilayer OLEDs by sequential solution processing of multiple layers, Furthermore, the photophysical properties of these compounds can be easily controlled by simply changing the cyclometaliating ĈN llgand in order to tune the triplet energy within the range of 3.0-2.2 eV. This diversity makes these materials not only suitable for use in hole transporting and electron blocking but also as emissive layers of several colors. Therefore, these compounds are applied as effective materials for aii-soiutlon processed OLEDs with (PPZ-VB) 2vlrPPZ (1) acting as hole transporting and electron blocking layer and host material, as well as three other compounds, (PPZ-VB) 2lrDFPPY (2), (PPZ-VB) 2lrTPY(3), and (PPZVB) 2lrPQ(4), used as crosslinkable phosphorescent emitters.
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials