Light-emitting device including organic compound and metal complex

A light-emitting device comprising:

• an anode;
• a cathode;
• and
• an EL layer between the anode and the cathode,
• wherein the EL layer includes a light-emitting layer and an electron-transport layer,
• wherein the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal,
• wherein the organic compound having the electron-transport property comprises a π-electron deficient heteroaromatic ring skeleton,
• wherein an ordinary refractive index of the organic compound having the electron-transport property with respect to light with any of wavelengths in the range of 455 nm to 465 nm is greater than or equal to 1.50 and less than or equal to 1.75, and
• wherein an ordinary refractive index of the metal complex of the alkali metal with respect to light with any of wavelengths in the range of 455 nm to 465 nm is greater than or equal to 1.45 and less than or equal to 1.70.

A light-emitting device comprising:

• an anode;
• a cathode;
• and
• an EL layer between the anode and the cathode,
• wherein the EL layer includes a light-emitting layer and an electron-transport layer,
• wherein the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal,
• wherein the organic compound having the electron-transport property comprises a π-electron deficient heteroaromatic ring skeleton,
• wherein an ordinary refractive index of the organic compound having the electron-transport property with respect to light with a wavelength of 633 nm is greater than or equal to 1.45 and less than or equal to 1.70, and
• wherein an ordinary refractive index of the metal complex of the alkali metal with respect to the light with the wavelength of 633 nm is greater than or equal to 1.40 and less than or equal to 1.65.