Organic EL element, display device, and light-emitting device
First Claim
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, whereinthe 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, andthe 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.
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Accused Products
Abstract
The present invention aims to provide organic EL elements operating at low voltage to emit light at high intensity. For this aim, each EL element includes an anode, a cathode, a functional layer disposed between the anode and the cathode and including a light-emitting layer composed of organic material, a hole injection layer disposed between the anode and the functional layer, and a bank defining the light-emitting layer. The hole injection layer contains tungsten oxide and exhibits: by UPS measurement, a UPS spectrum having a protrusion appearing near a Fermi surface and within a region corresponding to a binding energy range lower than the top of a valence band; and by XPS measurement, that the tungsten oxide in the hole injection layer satisfies a condition that a ratio in number density of atoms other than tungsten atoms and oxygen atoms to the tungsten atoms is equal to 0.83 or smaller.
81 Citations
20 Claims
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1. An organic electroluminescent (EL) element, comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 17, 18, 19)
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10. An organic electroluminescent (EL) element, comprising:
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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, whereinthe hole injection layer contains a tungsten oxide, an Ultraviolet Photoelectron Spectroscopy (UPS) spectrum, obtained from an UPS measurement having; 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, and a peak appearing within a another region corresponding to a binding energy range from 4.5 eV to 5.4 eV, an inner portion of the hole injection layer is depressed to define a recess, and 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, and 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. - View Dependent Claims (11, 12, 13, 14, 15, 16, 20)
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Specification