Organic electroluminescence device

• US 9,147,714 B2
• Filed: 11/27/2013
• Issued: 09/29/2015
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kashiwabara, Mitsuhiro
• Primary Examiner(s): GREEN, TELLY D
• Application Number:
  US14/092,327
• Publication Number:
  US 20140151663A1
• Time in Patent Office: 671 Days
• Field of Search: 257/40, 257/98, 257/E33.001, 257/E51.022, 257/765, 257/89
• US Class Current: 1/1
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/805 Electrodes

Abstract

An organic EL device having a red light emitting area and a green light emitting area is provided. Each of the red light emitting area and the green light emitting area has a structure such that a first electrode having a light transmitting characteristic and an organic layer formed on the first electrode are stacked, and a second electrode having a light reflecting characteristic is disposed on the organic layers of the red and green light emitting areas. Reflectance of green light by the second electrode in the red light emitting area is smaller than reflectance of green light in the second electrode of the green light emitting area. Reflectance of red light by the second electrode of the red light emitting area is larger than reflectance of red light by the second electrode of the green light emitting area.

Claims

1. An organic EL device comprising:

a red light emitting area including a first red electrode having a light transmitting characteristic, an organic layer, and a reflector having a first light reflecting characteristic, the first red electrode, the organic layer, and the reflector being stacked;

a green light emitting area including a first green electrode having a light transmitting characteristic and an organic layer and excluding the reflector, the first green electrode and the organic layer being stacked; and

a second electrode on the organic layer of the red light emitting area and on the organic layer of the green light emitting area, the second electrode having a second light reflecting characteristic, wherein the reflector includes a material and thickness to cause;

reflectance of green light produced by a combination of the first light reflecting characteristic of the reflector and the second light reflecting characteristic of the second electrode in the red light emitting area to be smaller than reflectance of green light by the second electrode in the red light emitting area taken alone; and

reflectance of red light produced by a combination of the first light reflecting characteristic of the reflector and the second light reflecting characteristic of the second electrode in the red light emitting area is larger than reflectance of red light by the second electrode in the red light emitting area taken alone.

2. The organic EL device as claimed in claim 1, wherein the reflector in the red light emitting area comprises a layer including copper.

3. The organic EL device as claimed in claim 2, wherein

a thickness of the layer including the copper is between 5 nm and 50 nm and

the second electrode of the red light emitting area is formed on the layer including copper and of a material including aluminum or silver.

4. The organic EL device as claimed in claim 3, wherein the organic layer of the red light emitting area and the organic layer of the green light emitting area have one or more common layers except for a light emitting layer.

5. The organic EL device as claimed in claim 1, wherein a red reflectance in the red light emitting area is centered on light having a wavelength of 620 nm.

6. The organic EL device as claimed in claim 5, wherein green reflectance in the red light emitting area is centered on light having a wavelength of 550 nm.

7. The organic EL device as claimed in claim 1, wherein the reflector comprises a layer including gold.

8. The organic EL device as claimed in claim 7, wherein the second electrode of the red light emitting area is formed on the layer including gold and of a material including aluminum or silver.

9. The organic EL device as claimed in claim 8, wherein the organic layer of the red light emitting area and the organic layer of the green light emitting area have one or more common layers except for a light emitting layer.