Solution processable phenothiazine dioxide/spiro‑9，9′‑xanthene fluorene host material and its luminescence device

The organic small molecular spiro compound 2-（10-dioxothiazinyl）-spiro-9，9'-oxanthrene fluorene （SFX-PzO₂） was employed as host material. ［Ir（pq）₂acac］ and ［Ir（mppy）₃］ ， as red and green phosphor guest materials， were doped into the host material with the doping ratio of 6% and 4%， respectively. The red and green phosphorescent organic light-emitting diodes based on organic small molecule SFX-PzO₂ were successfully fabricated via solution-processing method using chlorobenzene as solvent. The device performance results showed that the luminance of red and green phosphorescent devices reached 1000 cd/m² at the driving voltages of 11.5 V and 12.7 V， respectively， which indicates that the two devices can be used in portable equipment because of their low driving voltage. The maximum current efficiency values of red and green PhOLEDs were 4.89 cd/A and 5.88 cd/A， respectively.