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Organic electroluminescence device with prescribed optical path length

Imported: 23 Feb '17 | Published: 22 Oct '02

Kenichi Fukuoka, Mitsuru Eida

USPTO - Utility Patents

Abstract

An organic ELECTROLUMINESCENCE device exhibiting a minimal change in the color purity (CIE chromaticity coordinates) even if there is some fluctuation in the optical path length, and a method of manufacturing such an organic EL device are provided.

The organic EL device contains an organic layer formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length (t) of the transparent electrode and the organic layer satisfies the following inequality (a) or inequality (b) or both:

Min−20 nm<

t<Min+20 nm  (a)

Max−20 nm<

t<Max+20 nm  (b)

wherein t is the total optical path length (nm), Min is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibits a minimum value, and Max is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of the organic EL device in the first and second embodiments.

FIG. 2 is a drawing showing the relationship between the total optical path length (t

1) of a transparent electrode and a blue light emitting organic layer and the CIEx chromaticity coordinate value of EL luminescence.

FIG. 3 is a drawing showing the relationship between the total optical path length (t

1) of a transparent electrode and a blue light emitting organic layer and the CIEy chromaticity coordinate value of EL luminescence.

FIG. 4 is a drawing showing the CIE chromaticity coordinates of blue light luminescence.

FIG. 5 is a drawing showing an enlarged view of the CIE chromaticity coordinates of blue light luminescence.

FIG. 6 is a drawing showing the relationship between the interference peak (A

1) and the intensity peak (B

1) of the blue light emitting organic layer in the first embodiment.

FIG. 7 is a drawing showing the relationship between the interference peak (A

2) and the intensity peak (B

2) of the blue light emitting organic layer in a conventional organic EL device.

FIG. 8 is a drawing showing the relationship between the total optical path length (t

3) of a transparent electrode and a green light emitting organic layer and the CIEx chromaticity coordinate value of EL luminescence.

FIG. 9 is a drawing showing the relationship between the total optical path length (t

3) of a transparent electrode and a green light emitting organic layer and the CIEy chromaticity coordinate value of EL luminescence.

FIG. 10 is a drawing showing the CIE chromaticity coordinates of green light luminescence.

FIG. 11 is a drawing showing an enlarged view of the CIE chromaticity coordinates of green light luminescence.

FIG. 12 is a drawing showing the relationship between the interference peak (A

1) and the intensity peak (B

1) of the green light emitting organic layer in the second embodiment.

FIG. 13 is a drawing showing the relationship between the interference peak (A

2) and the intensity peak (B

2) of the green light emitting organic layer in a conventional organic EL device.

FIG. 14 shows a cross-sectional view of the organic EL device in the third embodiment.

FIG. 15 is a drawing showing the relationship between the total optical path length (t

2) of a transparent electrode and a red light emitting organic layer and the CIEx chromaticity coordinate value of EL luminescence.

FIG. 16 is a drawing showing the relationship between the total optical path length (t

2) of a transparent electrode and a red light emitting organic layer and the CIEy chromaticity coordinate value of EL luminescence.

FIG. 17 is a drawing showing the CIE chromaticity coordinates of red light luminescence.

FIG. 18 is a drawing showing an enlarged view of the CIE chromaticity coordinates of red light luminescence.

FIG. 19 is a drawing showing the relationship between the interference peak (A

1) and the intensity peak (B

1) of the red light emitting organic layer in the third embodiment.

FIG. 20 is a drawing showing the relationship between the interference peak (A

2) and the intensity peak (B

2) of the red light emitting organic layer in a conventional organic EL device.

FIG. 21 shows a cross-sectional view of the organic EL device in the fourth embodiment.

FIG. 22 is a drawing showing the organic EL device in Example 7.

FIG. 23 is a drawing showing the organic EL device in Example 8.

FIG. 24 is a drawing for comparing the relationship between the total optical path length and the CIEy chromaticity coordinate value of EL luminescence in Example 2 and Comparative Example 3.

FIG. 25 is a drawing for comparing the relationship between the total optical path length and the CIEx chromaticity coordinate value of EL luminescence in Example 3 and Comparative Example 4.

FIG. 26 is a drawing for comparing the relationship between the total optical path length and the CIEy chromaticity coordinate value of EL luminescence in Example 1 and Comparative Examples 1 and 2.

FIG. 27 is a drawing for comparing the relationship between the total optical path length and the CIEy chromaticity coordinate value of EL luminescence in Examples 7 to 9 and Comparative Example 5.

FIG. 28 is a drawing showing the relationship between the total optical path length and each CIEx chromaticity coordinate value of EL luminescence in the case where a GCCM is combined in the first embodiment.

FIG. 29 is a drawing showing the relationship between the total optical path length and each CIEy chromaticity coordinate value of EL luminescence in the case where a GCCM is combined in the first embodiment.

FIG. 30 is a drawing showing the relationship between the total optical path length and each CIEx chromaticity coordinate value of EL luminescence in the case where a RCCM is combined in the first embodiment.

FIG. 31 is a drawing showing the relationship between the total optical path length and each CIEy chromaticity coordinate value of EL luminescence in the case where a RCCM is combined in the first embodiment.

FIG. 32 is a drawing showing the relationship between the total optical path length (t

1) of a transparent electrode and a blue light emitting organic layer and the CIEx chromaticity coordinate value of EL luminescence when the total optical path length (t

1) is long.

FIG. 33 is a drawing showing the relationship between the total optical path length (t

1) of a transparent electrode and a blue light emitting organic layer and the CIEy chromaticity coordinate value of EL luminescence when the total optical path length (t

1) is long.

FIG. 34 is a drawing showing a vacuum deposition apparatus.

FIG. 35 is a drawing showing the relationship between the interference peak (

11) and the intensity peak (

12) in a conventional organic EL device.

Claims

1. An organic electroluminescence device containing an organic layer formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length t of the transparent electrode and the organic layer satisfies the following inequality (a) or inequality (b) or both:

Min−20 nm<

t<Min+20 nm  (a)

Max−20 nm<

t<Max+20 nm  (b)

wherein Min is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a minimum value, and Max is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value,

wherein (1) the total optical path length t of the transparent electrode and the organic layer coincides with the optical path length at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates exhibit a minimum value Min or the optical path length at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates exhibit a maximum value Max and (2) the intensity peak wavelength of the organic layer is in the range of about 400 to 490 nm and the total optical path length t of the transparent electrode an the organic layer coincide with the optical path length at which the CIEy chromaticity coordinates exhibit a minimum value Min.

2. An organic electroluminescence device comprising a blue light emitting organic layer having an intensity peak wavelength of about 400 to 490 nm, a green light emitting organic layer having an intensity peak wavelength of about 500 to 570 nm, and a red light emitting organic layer having an intensity peak wavelength of about 580 to 700 nm, formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length t

1 of the transparent electrode and the blue light emitting organic layer satisfies the inequality, Min−20 nm<t

1<Min+20 nm, wherein Min is the optical path length (nm) at which the CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a minimum value; the total optical path length t

3 of the transparent electrode and the green light emitting organic layer satisfies the inequality, Max−20 nm<t

3<Max+20 nm, wherein Max is the optical path length (nm) at which the CIEy.

3. The electroluminescence device according to claim 2, wherein the blue light emitting organic layer, the green light emitting organic layer and the red light emitting organic layer are arranged in substantially the same plane so as not to overlap with each other. chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value; or the total optical path length t

2 of the transparent electrode and the red light emitting organic layer satisfies the inequality, Max−20 nm<t

2<Max+20 nm, wherein Max is the optical path length (nm) at which the CIEx chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value.

4. An electroluminescence device comprising a blue light emitting organic layer having an intensity peak wavelength of about 400 to 490 nm, a green light emitting organic layer having an intensity peak wavelength of about 500 to 570 nm, and a red light emitting organic layer having an intensity peak wavelength of about 580 to 700 nm, formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length t

1 of the transparent electrode and the blue light emitting organic layer satisfies the inequality, Min−20 n=<t

1<Min+20 nm, wherein Min is the optical path length (nm) at which the CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a minimum value; the total optical path length t

3 of the transparent electrode and the green light emitting organic layer satisfies the inequality, Max−20 nm<t

3<Max+20 nm, wherein Max is the optical path length (nm) at which the CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value; and the total optical path length t

2 of the transparent electrode and the red light emitting organic layer satisfies the inequality, Max−20 nm<t

2<Max+20 nm, wherein Max is the optical path length (nm) at which the CIEx chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value.

5. An organic electroluminescence device containing an organic layer formed between electrodes at least one of which is a transparent electrode and an optical path length correcting layer for adjusting an optical path length, wherein the total optical path length t of the transparent electrode, the organic layer and the optical path length correcting layer satisfies the following inequality (a) or inequality (b) or both:

Min−20 nm<

t<Min+20 nm  (a)

Max−20 nm<

t<Max+20 nm  (b)

wherein t is the total optical path length (nm), Min is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a minimum value, and Max is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value.

6. An electroluminescence device containing an organic layer formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length t of the transparent electrode and the organic layer satisfies the following inequality (a) or inequality (b) or both:

Min−20 nm<

t<Min+20 nm  (a)

Max−20 nm=<

t<Max+20 nm  (b)

wherein Min is the optical path length (nm) at which the CIEx chromaticity coordinates or ClEy chromaticity coordinates measured according to JIS Z 8701 exhibit a minimum value, and Max is the optical path length (nm) at which the CIEx chromaticity coordinates or ClEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value, wherein the organic layer is a blue light emitting organic layer having an intensity peak wavelength of about 400 to 490 nm.

7. The electroluminescence device according to claim 6, wherein the blue light emitting organic layer has a thickness of at least 2,000 nm.