摘要 |
<p>An organic EL element has an anode, a cathode, a hole injection layer and at least one functional layer disposed between the anode and the cathode. The at least one functional layer contains an organic material. Holes are injected into the functional layer from the hole injection layer, which contains a tungsten oxide. A Ultraviolet Photoelectron Spectroscopy (UPS) spectrum obtained from a UPS measurement has a protrusion near a Fermi surface and within a region corresponding to a binding energy range lower than a top of the valence band. The tungsten oxide contained in the hole injection layer satisfies a condition, determined from an X-ray Photoelectronic Spectroscopy measurement, that a ratio in a number density of atoms other than tungsten and oxygen atoms to the tungsten atoms does not exceed approximately 0.83.</p> |