Organic light-emitting diode having an interface layer between the hole-transporting layer and the light-emitting layer

An organic light-emitting device comprising, in sequence:

• a substrate;
• b) an anode;
• c) a hole-transporting layer having a hole-transporting organic compound;
• d) a single interface layer disposed on the hole-transporting layer in a range of thickness between 0.1 nm to 5 nm, and wherein the potential barrier between the hole-transporting layer and the interface layer is greater than 0.6 eV and the energy bandgap of the interface layer is 3.0 eV or greater;
• e) a light-emitting layer disposed on the interface layer having a light-emitting organic compound;
• f) an electron-transporting layer having an electron-transporting organic compound;
• and
• g) a cathode;
• wherein the interface layer contains a compound having an ionization potential greater than that of the organic compound of the hole-transporting layer, and an energy bandgap equal to or greater than that of the organic compound of the light-emitting layer.