An light emitting device of the present embodiments includes oppositely disposed first electrode and second electrode, and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one among the plurality of organic layers includes a fused polycyclic compound represented by Formula 1 below, thereby showing improved emission efficiency: ##STR00001##

An light emitting device of the present embodiments includes oppositely disposed first electrode and second electrode, and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one among the plurality of organic layers includes a fused polycyclic compound represented by Formula 1 below, thereby showing improved emission efficiency:

##STR00001##

Provided are multi-NBN host compounds. The compound has the structure of Formula I:

##STR00001##

Also provided are formulations comprising these multi-NBN host compounds. Further provided are OLEDs and related consumer products that utilize these multi-NBN host compounds.