Organic EL display device and organic EL display device manufacturing method

Patent metadata

Field	Value
Publication number	US-10873050-B2
Application number	US-201716088458-A
Country	US
Kind code	B2
Filing date	Mar 22, 2017
Priority date	Mar 29, 2016
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

An organic EL display device with higher resolution, suppressed power consumption while being driven and low manufacturing cost, and no color mixing and color shifting between subpixels adjacent to each other is provided. In a B subpixel, a first separation layer is provided between a common blue-light-emitting layer and a common green-light-emitting layer. In a G subpixel, a second separation layer is provided between the common green-light-emitting layer and a common red-light-emitting layer.

First claim

The invention claimed is:

1. An organic electro luminescence (EL) display device comprising:
a plurality of pixels each including:
a first subpixel;
a second subpixel; and
a third subpixel,
the first, second, and third subpixels being configured to emit light with peak wavelengths different from each other, and
the first, second, and third subpixels each including:
a positive electrode;
a negative electrode; and
a light-emitting layer formed between the positive electrode and the negative electrode,

wherein either of the positive electrode and the negative electrode is a reflective electrode or includes a reflective layer, and another of the positive electrode and the negative electrode is a transparent electrode or a translucent electrode configured to transmit the light with peak wavelengths different from each other,
the light-emitting layer is a layered film including:
a first fluorescence light-emitting layer configured to emit light with a longest peak wavelength;
a second fluorescence light-emitting layer configured to emit light with a shortest peak wavelength; and
a third fluorescence light-emitting layer configured to emit light with a peak wavelength between the longest peak wavelength of the first fluorescence light-emitting layer and the shortest peak wavelength of the second fluorescence light-emitting layer,

the first fluorescence light-emitting layer, the second fluorescence light-emitting layer, and the third fluorescence light-emitting layer are each formed as a single common layer in the plurality of pixels,
the first fluorescence light-emitting layer is arranged above or below the second fluorescence light-emitting layer and the third fluorescence light-emitting layer,
in the first subpixel, a first separation layer without including a light-emitting material is provided between the second fluorescence light-emitting layer and the third fluorescence light-emitting layer, and
in the second subpixel, a second separation layer without containing a light-emitting material is provided between the first fluorescence light-emitting layer and a fluorescence light-emitting layer lying adjacent to the first fluorescence light-emitting layer.

2. The organic EL display device according to claim 1 , wherein
the first fluorescence light-emitting layer is a light-emitting layer for red light,
the second fluorescence light-emitting layer is a light-emitting layer for blue light, and
the third fluorescence light-emitting layer is a light-emitting layer for green light.

3. The organic EL display device according to claim 1 , wherein at least either of the first separation layer and the second separation layer is a layered film of a plurality of layers.

4. The organic EL display device according to claim 1 , wherein the first separation layer has a film thickness ranging from 15 nm to 50 nm, both inclusive.

5. The organic EL display device according to claim 1 , wherein the second separation layer has a film thickness ranging from 15 nm to 50 nm, both inclusive.

6. The organic EL display device according to claim 1 , wherein a third fluorescence light-emitting material contained in the third fluorescence light-emitting layer contains a thermally activated delayed fluorescence material with an energy difference of less than 0.3 eV between a minimum excited singlet level and a minimum excited triplet level.

7. The organic EL display device according to claim 1 ,
wherein a second block layer without containing a light-emitting material is formed between the second fluorescence light-emitting layer and the third fluorescence light-emitting layer as a single common layer in the plurality of pixels, and
in the first subpixel, a film thickness of the first separation layer and the second block layer ranges from 15 nm to 50 nm, both inclusive.

8. The organic EL display device according to claim 1 , wherein a wavelength range of a light-emitting spectrum of the second fluorescence light-emitting material contained in the second fluorescence light-emitting layer and a wavelength range of an absorption spectrum of the third fluorescence light-emitting material contained in the third fluorescence light-emitting layer overlap with each other within a predetermined wavelength range.

9. The organic EL display device according to claim 1 , wherein a wavelength range of a light-emitting spectrum of the third fluorescence light-emitting material contained in the third fluorescence light-emitting layer and a wavelength range of an absorption spectrum of a first fluorescence light-emitting material contained in the first fluorescence light-emitting layer overlap with each other within a predetermined wavelength range.

10. The organic EL display device according to claim 1 , wherein a wavelength range of an absorption spectrum of the first separation layer does not overlap with the wavelength range of the light-emitting spectrum of the second fluorescence light-emitting material contained in the second fluorescence light-emitting layer.

11. The organic EL display device according to claim 1 , wherein a wavelength range of an absorption spectrum of the second separation layer does not overlap with the wavelength range of the light-emitting spectrum of the third fluorescence light-emitting material contained in the third fluorescence light-emitting layer.

12. The organic EL display device according to claim 1 ,
wherein, between the positive electrode and the negative electrode, among the first fluorescence light-emitting layer, the second fluorescence light-emitting layer, and the third fluorescence light-emitting layer, the first fluorescence light-emitting layer is arranged most adjacent to the negative electrode, and the second fluorescence light-emitting layer is arranged most adjacent to the positive electrode, and
electron mobility of a material contained at a combination ratio of 50% or higher in a layer formed above the second fluorescence light-emitting layer, and between the second fluorescence light-emitting layer and the negative electrode is higher than hole mobility.

13. The organic EL display device according to claim 1 ,
wherein, between the positive electrode and the negative electrode, among the first fluorescence light-emitting layer, the second fluorescence light-emitting layer, and the third fluorescence light-emitting layer, the first fluorescence light-emitting layer is arranged most adjacent to the positive electrode, and the second fluorescence light-emitting layer is arranged most adjacent to the negative electrode, and
hole mobility of a material contained at a combination ratio of 50% or higher in a layer formed below the second fluorescence light-emitting layer, and between the second fluorescence light-emitting layer and the positive electrode is higher than electron mobility.

14. The organic EL display device according to claim 1 ,
wherein, between the positive electrode and the negative electrode, among the first fluorescence light-emitting layer, the second fluorescence light-emitting layer, and the third fluorescence light-emitting layer, the first fluorescence light-emitting layer is arranged most adjacent to the negative electrode, and the third fluorescence light-emitting layer is arranged most adjacent to the positive electrode,
electron mobility of a material contained at a combination ratio of 50% or higher in a layer formed above the second fluorescence light-emitting layer, and between the second fluorescence light-emitting layer and the negative electrode is higher than hole mobility, and
hole mobility of a material contained at a combination ratio of 50% or higher in a layer forme

Assignees

• Sharp Kk

Inventors

• Tsukamoto Yuto
• Mitsui Seiichi
• Kawato Shinichi
• Niboshi Manabu
• Koike Eiji
• Ohara Masanori
• ITO Asae

Classifications

• H10K71/00

  Manufacture or treatment specially adapted for the organic devices covered by this subclass · CPC title

• H10K50/131

  with spacer layers between the electroluminescent layers · CPC title

• G09F9/30 Primary

  in which the desired character or characters are formed by combining individual elements (panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00) · CPC title

• H05B33/10

  Apparatus or processes specially adapted to the manufacture of electroluminescent light sources · CPC title

• H05B33/12

  Light sources with substantially two-dimensional [2D] radiating surfaces · CPC title