A solution-processable bipolar molecular glass as a host material for white electrophosphorescent devices

A solution-processable bipolar material tBu-OXDTFA comprising an electron-rich triphenylamine core and electron-deficient oxadiazole/fluorene peripheries was synthesized. This dendrimer-like molecule not only possesses a high triplet energy (2.74 eV) but also exhibits excellent film-forming properties upon solution processing. We achieved highly efficient white electrophosphorescent OLEDs (22.3 cd A−1, 11.6%) through solution processing, wherein the single white emitting layer was readily formed after spin-coating a solution of blue- and red-phosphor co-dopants containing tBu-OXDTFA as the host matrix.