Organic light emitting pixel and organic light emitting display device including the same

Patent metadata

Field	Value
Publication number	US-2017033306-A1
Application number	US-201615069997-A
Country	US
Kind code	A1
Filing date	Mar 15, 2016
Priority date	Jul 29, 2015
Publication date	Feb 2, 2017
Grant date	—

Abstract

An organic light emitting pixel and an organic light emitting display device, the pixel including a first organic light emitting diode to emit light with a n th order resonance mode of a first wavelength, n being a natural number of at least 1; a second organic light emitting diode to emit light with the n th order resonance mode of a second wavelength, the second wavelength being shorter than the first wavelength; and a third organic light emitting diode to emit light with a m th order resonance mode of a third wavelength, the third wavelength being shorter than the first and second wavelengths, and m being a natural number that is larger than n.

First claim

What is claimed is:

1 . An organic light emitting pixel, comprising:
a first organic light emitting diode to emit light with a n th order resonance mode of a first wavelength, n being a natural number of at least 1; a second organic light emitting diode to emit light with the n th order resonance mode of a second wavelength, the second wavelength being shorter than the first wavelength; and a third organic light emitting diode to emit light with a m th order resonance mode of a third wavelength, the third wavelength being shorter than the first and second wavelengths, and m being a natural number that is larger than n.

2 . The organic light emitting pixel as claimed in claim 1 , wherein:
the first organic light emitting diode includes a first anode, a first hole control layer on the first anode, a first resonance control layer on the first hole control layer, a first light emitting layer on the first resonance control layer, a first electron control layer on the first light emitting layer, and a first cathode on the first electron control layer; the second organic light emitting diode includes a second anode, a second hole control layer on the second anode, a second resonance control layer on the second hole control layer, a second light emitting layer on the second resonance control layer, a second electron control layer on the second light emitting layer, and a second cathode on the second electron control layer, the second cathode being a single body with the first cathode; and the third organic light emitting diode includes a third anode, a third hole control layer on the third anode, a third resonance control layer on the third hole layer, a third light emitting layer on at least the third resonance control layer, a third electron control layer on the third light emitting layer, and a third cathode on the third electron control layer, the third cathode being a single body with the second cathode.

3 . The organic light emitting pixel as claimed in claim 2 , wherein:
the first hole control layer, the second hole control layer, and the third hole control layer are a single body, and the first hole control layer, the second hole control layer, and the third hole control layer being the single body is a common hole control layer.

4 . The organic light emitting pixel as claimed in claim 3 , wherein the common hole control layer includes a hole transport layer that transports holes to the first to third light emitting layers.

5 . The organic light emitting pixel as claimed in claim 4 , wherein:
the hole transport layer includes a doped layer and an undoped layer that are divided in a thickness direction of the hole transport layer, the undoped layer being closer to the first to third light emitting layers than is the doped layer, the doped layer includes a p-type dopant and a hole transport material, and the undoped layer includes a hole transport material.

6 . The organic light emitting pixel as claimed in claim 4 , wherein the common hole control layer further includes a hole injection layer that injects holes from the first to third anodes to the hole transport layer.

7 . The organic light emitting pixel as claimed in claim 3 , further comprising an intermediate layer that is between the common hole control layer and the first to third anodes and that generates holes.

8 . The organic light emitting pixel as claimed in claim 7 , wherein the intermediate layer includes hexaazatriphenylene hexacarbonitrile, molybdenum trioxide, or fullerene.

9 . The organic light emitting pixel as claimed in claim 3 , wherein:
the first electron control layer, the second electron control layer, and the third electron control layer are a single body, and the first electron control layer, the second electron control layer, and the third electron control layer being the single body are a common electron control layer.

10 . The organic light emitting pixel as claimed in claim 9 , wherein the third light emitting layer includes:
a first portion that overlaps with the first light emitting layer, a second portion that overlaps with the second light emitting layer, and a third portion that overlaps with the third resonance control layer.

11 . The organic light emitting pixel as claimed in claim 10 , wherein the third light emitting layer includes an ambipolar compound.

12 . The organic light emitting pixel as claimed in claim 11 , wherein the ambipolar compound includes anthracene, 9-phenylanthracene, 9,10-diphenylanthracene, or benzo(B)naphto(2,3-D)furan.

13 . The organic light emitting pixel as claimed in claim 10 , wherein:
the first portion is between the common hole control layer and the first light emitting layer, the second portion is between the common hole control layer and the second light emitting layer, and the third portion is between the third light emitting layer and the common electron control layer.

14 . The organic light emitting pixel as claimed in claim 13 , wherein the first resonance control layer has a LUMO level that is at least 0.2 eV higher than that of the first light emitting layer.

15 . The organic light emitting pixel as claimed in claim 10 , wherein:
the first portion is between the common electron control layer and the first light emitting layer, the second portion is between the common electron control layer and second light emitting layer, and the third portion is between the third light emitting layer and the common electron control layer.

16 . The light emitting pixel as claimed in claim 1 , wherein:
the first wavelength is about 620 to about 750 nm, the second wavelength is about 495 to about 570 nm, and the third wavelength is about 450 to about 495 nm.

17 . The light emitting pixel as claimed in claim 1 , wherein n is 1 and m is 2.

18 . The light emitting pixel as claimed in claim 1 , wherein:
the first organic light emitting diode has a first resonance length (Lc 1 ) according to the following Equation 1:

Lc



1

=

λ1

2

Nc



1

×
n

(

Equation



1

)

the second organic light emitting diode has a second resonance length (Lc 2 ) according to the following Equation 2:

Lc

Assignees

• Samsung Display Co Ltd

Inventors

• Song Hajin
• Park Heungsu
• Lee Bumsuk
• Lee Sangwoo
• Pyo Sangwoo

Classifications

• H10K59/19

  Segment displays · CPC title

• H10K59/876

  comprising a resonant cavity structure, e.g. Bragg reflector pair · CPC title

• H10K59/8052

  Cathodes · CPC title

• H10K50/17

  Carrier injection layers · CPC title

• H10K50/11

  characterised by the electroluminescent [EL] layers · CPC title