Bipolar asymmetric carbazole-based host materials for electrophosphorescent guest-host OLED systems

摘要

An organic light-emitting device (OLED) in which a bipolar carbazole-based material expressed according to the following general formula: chemistry chemdraw filechemistry mol file;is used as a host material in a guest-host layer, such as the emissive layer and/or one of the charge transport layers. In the general formula above, R₁ represents an electron donating moiety or an electron accepting moiety; each R₂ to R₇ is present optionally; and each R₂ to R₇ independently represents an electron donating moiety or an electron accepting moiety.