Highly efficient exciplex organic light-emitting diodes incorporating a heptazine derivative as an electron acceptor

Highly efficient exciplex systems incorporating a heptazine derivative (HAP-3MF) as an electron acceptor and 1,3-di(9H-carbazol-9-yl)-benzene (mCP) as an electron donor are developed. An organic light-emitting diode containing 8 wt% HAP-3MF:mCP as an emitting layer exhibits a maximum external quantum efficiency of 11.3%.