Patent ID: 7645524

Claim:
A broadband-emitting OLED device comprising: a) an anode and a spaced cathode b) a hole-transporting layer provided between the anode and cathode, such hole-transporting layer including as a main component a first hole-transporting material which is selected from arylamine derivatives having a first glass transition temperature Tg1; c) a first light-emitting layer including as a main component 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) having a second glass transition temperature Tg2, such light-emitting layer disposed between the hole transporting layer and the cathode and in contact with the hole-transporting layer, and wherein Tg1 is greater than Tg2; and d) a second light-emitting layer disposed between the first light-emitting layer and the cathode; and wherein the first light-emitting layer emits light having a hue in a range of yellow to red, and the second light-emitting layer emits light having a hue in a range from blue to green.