Patent ID: 9130187
Filing Date: 2015-09-08
Classification: H01L

Abstract:
1. An organic electroluminescent (EL) element, comprising: an anode; a cathode; a functional layer disposed between the anode and the cathode, and including a light-emitting layer made of organic material; a hole injection layer disposed between the anode and the functional layer; and a bank that defines an area in which the light-emitting layer is to be formed, wherein the hole injection layer contains a tungsten oxide, an Ultraviolet Photoelectron Spectroscopy (UPS) spectrum, obtained from a UPS measurement, has a protrusion appearing near a Fermi surface and within a region corresponding to a binding energy range lower than a top of a valence band, the tungsten oxide contained in the hole injection layer satisfies a condition, determined from an X-ray Photoelectron Spectroscopy (XPS) measurement, that a ratio in a number density of atoms other than tungsten atoms and oxygen atoms to the tungsten atoms does not exceed 0.83, an inner portion of the hole injection layer is depressed to define a recess, an upper peripheral edge of the recess is covered with a part of the bank, the upper peripheral edge of the recess comprising at least a portion of an inner side surface of the recess, the UPS measurement includes parameters comprising He I as a light source and a normal line direction to a surface of the substrate as an electron emission angle, and the XPS measurement includes parameters comprising Al Kα as the light source and the normal line direction to the surface of the substrate as the electron emission angle.