Organic light-emitting diode display device having deep and sky blue sub-pixels

• US 8,680,518 B2
• Filed: 11/01/2012
• Issued: 03/25/2014
• Est. Priority Date: 11/01/2011
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Yong-Chul, Yoo, Juhn-Suk
• Primary Examiner(s): Soward, Ida M
• Application Number:
  US13/666,065
• Publication Number:
  US 20130105778A1
• Time in Patent Office: 509 Days
• Field of Search: 257/40, 257/59, 257/72, 257/89, 257/E51.022
• US Class Current: 257/40
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/805 Electrodes
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

Provided is an organic light-emitting diode (OLED) display device having sub-pixels with four colors. When a B1 sub-pixel that represents deep blue and a B2 sub-pixel that represents sky blue are formed, by using a high efficiency blue organic material to form the same emission material layers in both the B1 and B2 sub-pixels such that a microcavity effect is implemented only in the B2 sub-pixel and a sky blue peak is extracted from the high efficiency blue organic material of the B2 sub-pixel, the emission material layer of the B2 sub-pixel represents sky blue. Therefore, a process of depositing emission material layers is simplified, which leads to a short process time and a reduction of the cost of materials, resulting in improvement in process efficiency of the OLED display device.

Claims

1. An organic light-emitting diode (OLED) display device in which a red sub-pixel, a green sub-pixel, a deep blue sub-pixel, and a sky blue sub-pixel form a pixel, comprising:

an organic light-emitting layer in which the red sub-pixel includes a red light-emitting material layer, the green sub-pixel includes a green light-emitting layer, and the deep blue sub-pixel and the sky blue sub-pixel include the same blue light-emitting material layers; and

an organic light-emitting diode including a first electrode and a second electrode for each sub-pixel,

wherein the first electrode of the sky blue sub-pixel includes a reflection layer, the second electrode of the sky blue sub-pixel is semi-transparent, and the sky blue sub-pixel represents sky blue through a microcavity effect.

2. The OLED display device according to claim 1, wherein the blue light-emitting material layer has a deep blue peak and a light blue peak, and a sky blue peak is extracted from the blue light-emitting material layer by the microcavity effect.

3. The OLED display device according to claim 1, wherein the microcavity effect is implemented due to the blue light-emitting material layers or peripheral layers of the sky blue sub-pixel having different thickness combinations from the red sub-pixel, the green sub-pixel, and the deep blue sub-pixel.

4. The OLED display device according to claim 3, wherein the peripheral layers comprise a hole transport layer and a hole injection layer between the blue light-emitting material layer and the first electrode, and an electron transport layer and an electron injection layer between the blue light-emitting material layer and the second electrode.

5. The OLED display device according to claim 1, wherein the first electrodes of the red sub-pixel and the green sub-pixel comprise reflection layers, and the second electrodes are semi-transparent.

6. The OLED display device according to claim 1, wherein the deep blue sub-pixel or the sky blue sub-pixel have two or three times the areas of the red sub-pixel and the green sub-pixels.