公开(公告)号：US20210336176A1

公开(公告)日：2021-10-28

申请号：US17237262

申请日：2021-04-22

Applicant: Semiconductor Energy Laboratory Co., Ltd.

Inventor： Yuta KAWANO ,  Airi UEDA ,  Takeyoshi WATABE ,  Nobuharu OHSAWA ,  Keito TOSU ,  Harue OSAKA ,  Satoshi SEO ,  Ryo NARUKAWA ,  Shiho NOMURA

IPC: H01L51/50 ,  H01L27/32

Abstract: A light-emitting device with high emission efficiency is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the anode and the cathode. The EL layer includes a light-emitting layer and an electron-transport layer; the light-emitting layer includes a light-emitting material; the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal; the ordinary refractive index of the organic compound having an electron-transport property in a peak wavelength of light emitted from the light-emitting material is greater than or equal to 1.50 and less than or equal to 1.75; and the ordinary refractive index of the metal complex of an alkali metal in the peak wavelength of the light emitted from the light-emitting material is greater than or equal to 1.45 and less than or equal to 1.70.