Patent ID: 9401493
Filing Date: 2016-07-26
CPC Classification: H01L

Claim Text:
1. A method for manufacturing an organic electroluminescent element including a homojunction-type positive and negative charge transport layer having a hole transporting capability and an electron transporting capability interposed between an anode and a cathode, the method comprising: (a) a step of forming the positive and negative charge transport layer, comprising the sub-steps of: (i) forming a light-emitting region comprising an organic light-emitting material by doping a host material with a light-emitting dopant; (ii) forming at least one of the following blocking regions: an electron blocking region, provided closer to the anode than the light-emitting region, having a lowest unoccupied molecular orbital (LUMO), an absolute value of the LUMO being smaller than that of a lowest unoccupied molecular orbital of the light-emitting region, wherein a difference in the lowest unoccupied molecular orbital between the electron blocking region and the light-emitting region is not less than 1 eV; and a hole blocking region, provided closer to the cathode than the light-emitting region, having a highest occupied molecular orbital (HOMO), an absolute value of the HOMO being larger than that of a highest occupied molecular orbital of the light-emitting region; and (iii) forming a hole injection transport region on the anode and an electron injection transport region on the hole blocking region, respectively, wherein in a direction from the anode to the cathode, the hole injection transport region, the electron blocking region, the light-emitting region, the hole blocking region, and the electron injection transport region are sequentially arranged, and wherein the step (a) forms the positive and negative charge transport layer to be a thin layer by reaction of at least one of organic material components for the positive and negative charge transport layer on a surface of the substrate or in a vapor phase, wherein a concentration gradient of the organic light-emitting material continuously increases from respective end faces of the light-emitting region on an electron blocking region side and on a hole blocking region side toward a center of the light-emitting region so that optical and electrical losses caused by a difference in refractive index and mobility between materials of separated layers can be reduced.