Light-Emitting Element and Display Device

• US 20160268348A1
• Filed: 05/18/2016
• Published: 09/15/2016
• Est. Priority Date: 05/20/2004
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ikeda, Hisao, Ohara, Hiroki, Hosoba, Makoto, Sakata, Junichiro, Ito, Shunichi
• Granted Patent: US 9,614,012 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H10K 2102/00 Constructional details relating to the organic devices covered by this subclass
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/84 Passivation; Containers; Encapsulations
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/8428 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/126 : Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/35 : comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 : comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/80524 : Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/8722 : Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/8723 : Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 59/873 : Encapsulations
• CPC Class Codes: H10K 59/879 : comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/8792 : comprising light absorbing layers, e.g. black layers

Abstract

There has been a problem that difference in refractive index between an opposite substrate or a moisture barrier layer provided thereover, and air is maintained large, and light extraction efficiency is low. Further, there has been a problem that peeling or cracking due to the moisture barrier layer is easily generated, which leads to deteriorate the reliability and lifetime of a light-emitting element. A light-emitting element comprises a pixel electrode, an electroluminescent layer, a transparent electrode, a passivation film, a stress relieving layer, and a low refractive index layer, all of which are stacked sequentially. The stress relieving layer serves to prevent peeling of the passivation film. The low refractive index layer serves to reduce reflectivity of light generated in the electroluminescent layer in emitting to air. Therefore, a light-emitting element with high reliability and long lifetime and a display device using the light-emitting element can be provided.

Claims

1. A light-emitting element comprising:

a pixel electrode;

an electroluminescent layer formed over the pixel electrode;

a transparent electrode formed over the electroluminescent layer;

a passivation film formed over the transparent electrode;

a stress relieving layer formed over the passivation layer; and

a low refractive index layer formed over the stress relieving layer.