Patent ID: 7332857

Claim:
A light emitting, device comprising an organic light emitting element comprising: an anode; a cathode; and an organic compound film sandwiched between the anode and the cathode, wherein the organic compound film comprises: a first layer comprising a first compound; a second layer comprising the first compound and a second compound; and a third layer comprising the second compound, wherein the first compound is a blocking compound capable of stopping the movement of holes or electrons, and wherein the second compound is at least one selected compound selected from the group consisting of: a hole injecting compound that receives holes from the anode; a hole transporting compound that has a hole mobility that is larger than its electron mobility; an electron transporting compound that has an electron mobility that is larger than is hole mobility; and an electron injecting compound that receives electrons from the cathode, wherein the blocking compound and the at least one compound selected are materials capable of undergoing vacuum evaporation, and wherein the electric current versus electric voltage property of the organic light emitting elements show a rectification property.