Patent ID: 8153275

Claim:
An organic electroluminescent element comprising a light emitting layer including an organic material between an anode and a cathode, comprising: a hole transport layer provided between the anode and the light emitting layer; an intermediate layer provided between the hole transport layer and the light emitting layer, wherein the intermediate layer has an energy level of a lowest unoccupied molecular orbital lower than energy levels of lowest unoccupied molecular orbitals of the hole transport layer and the light emitting layer; wherein the intermediate layer has an energy level of a highest occupied molecular orbital lower than energy levels of highest occupied molecular orbitals of the hole transport layer and the light emitting layer; wherein a difference between an energy level of a highest occupied molecular orbital of the light emitting layer and the energy level of the lowest unoccupied molecular orbital of the intermediate layer is approximately 1.5 eV or less; wherein the hole transport layer and the intermediate layer contact each other and the intermediate layer and light emitting layer contact each other; and further comprising a hole injection layer between the anode and the hole transport layer, wherein a difference between an energy level of a highest occupied molecular orbital of the hole transport layer and an energy level of a lowest unoccupied molecular orbital of the hole injection layer is approximately 1.5 eV or less; wherein the intermediate layer and the hole injection layer are comprised of a same material.