| abstract |
The present invention is directed at a new class of compounds containing an azadibenzothiophene or aza-dibenzofuran core are provided. In particular, azadibenzothiophene compounds or aza-dibenzofuran compounds further substituted with triphenylene and/or nitrogen-containing substituents are provided. These compounds may be advantageously used in phosphorescent organic light emitting devices. Preferably, these compounds may be used as a host material in an emissive layer or as a material in an enhancement layer. |