Invention Grant
- Patent Title: Light-emitting element, light-emitting device, lighting device, and electronic appliance
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Application No.: US14698140Application Date: 2015-04-28
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Publication No.: US10069097B2Publication Date: 2018-09-04
- Inventor: Riho Kataishi , Toshiki Sasaki , Satoshi Seo
- Applicant: Semiconductor Energy Laboratory Co., Ltd.
- Applicant Address: JP
- Assignee: Semiconductor Energy Laboratory Co., Ltd.
- Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
- Current Assignee Address: JP
- Agency: Husch Blackwell LLP
- Priority: JP2014-093657 20140430
- Main IPC: H01L27/32
- IPC: H01L27/32 ; H01L51/00 ; H01L51/50 ; H01L51/52 ; H01L29/786 ; H01L29/24

Abstract:
An inverted-structure light-emitting element is provided. One embodiment of the invention disclosed in this specification is a light-emitting element including a cathode, a layer serving as a buffer over the cathode, an electron-injection layer over the layer serving as a buffer, a light-emitting layer over the electron-injection layer, and an anode over the light-emitting layer. The electron-injection layer includes an alkali metal or an alkaline earth metal. The layer serving as a buffer includes an electron-transport material. In the inverted-structure light-emitting element, contact of the alkali metal or alkaline earth metal included in a material of the electron-injection layer with the already formed cathode increases the driving voltage of an EL element and reduces emission efficiency. This problem becomes prominent particularly when the cathode includes an oxide conductive film. To prevent this, the layer serving as a buffer is provided between the cathode and the electron-injection layer.
Public/Granted literature
- US20150318335A1 Light-Emitting Element, Light-Emitting Device, Lighting Device, and Electronic Appliance Public/Granted day:2015-11-05
Information query
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