Light-emitting element, light-emitting device, display device, electronic device, and lighting device

A light-emitting element comprising:

• a first electrode;
• a first light-emitting layer;
• a second light-emitting layer;
• and
• a second electrode,
• wherein the first light-emitting layer is between the first electrode and the second light-emitting layer,
• wherein the second light-emitting layer is between the first light-emitting layer and the second electrode,
• wherein the first light-emitting layer comprising:
• a first iridium complex;
• a first host material;
• and
• a first organic compound,
• wherein the second light-emitting layer comprising:
• a second iridium complex;
• and
• a second host material,
• wherein the first host material and the first organic compound form an exciplex,
• wherein light emitted from the second iridium complex has a longer wavelength than light emitted from the first iridium complex,
• wherein a difference between an emission peak wavelength of a photoluminescence spectrum F(λ) of the exciplex and a wavelength of the longest-wavelength-side local maximum of a function ε(λ)λ4 of the first iridium complex is 0.2 eV or less when converted into energy,
• wherein a difference between an emission peak wavelength of a photoluminescence wherein a difference between an emission peak wavelength of a photoluminescence spectrum F(λ) of the first iridium complex and a wavelength of the longest-wavelength-side local maximum of a function ε(λ)λ4 of the second iridium complex is 0.2 eV or less when converted into energy,
• wherein λ denotes a wavelength, and
• wherein ε(λ) denotes a molar absorption coefficient at the wavelength λ.