Hole-trapping materials for improved OLED efficiency

An organic light-emitting device includes a light-emitting layer including a host, a dopant, and a hole-trapping material, wherein the hole-trapping material is provided at 0.01 to less than 5% by volume relative to the light-emitting layer volume, has an oxidation potential that is selected so that it is less than the oxidation potential of the host in order to serve as a hole trap, has an oxidation potential that is selected so as to avoid formation of a certain charge transfer complex between the hole-trapping material and the host if the charge transfer complex causes a reduction in the electroluminescent efficiency of the dopant, and has an oxidation potential that is selected so as to avoid formation of the charge transfer complex between the hole-trapping material and the dopant.