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

A light-emitting device comprising a pixel portion, the pixel portion comprising:

• a first transistor;
• a second transistor;
• a third transistor;
• a fourth transistor;
• a first light-emitting element electrically connected to the first transistor, the first light-emitting element comprising a first anode, a first light-emitting layer over the first anode, a second light-emitting layer over the first light-emitting layer, and a cathode over the second light-emitting layer;
• a second light-emitting element electrically connected to the second transistor, the second light-emitting element comprising a second anode, the first light-emitting layer over the second anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a third light-emitting element electrically connected to the third transistor, the third light-emitting element comprising a third anode, the first light-emitting layer over the third anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a fourth light-emitting element electrically connected to the fourth transistor, the fourth light-emitting element comprising a fourth anode, the first light-emitting layer over the fourth anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a red color filter under the first anode;
• a green color filter under the second anode;
• and
• a blue color filter under the third anode,
• wherein a color filter is not provided under the fourth anode,
• wherein each of the first transistor, the second transistor, the third transistor, and the fourth transistor comprises an oxide semiconductor,
• wherein each of the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element does not comprise a light-emitting layer between the first light-emitting layer and each of the first anode, the second anode, the third anode, and the fourth anode,
• wherein the first light-emitting layer is separated from the second light-emitting layer,
• wherein the first light-emitting layer comprises a fluorescent material and a host material,
• wherein the second light-emitting layer comprises a phosphorescent material, a first organic compound, and a second organic compound,
• wherein an emission spectrum of the fluorescent material has a peak in a wavelength region of greater than or equal to 420 nm and less than or equal to 480 nm,
• wherein an emission spectrum of the phosphorescent material has a peak in a yellow wavelength region,
• wherein the emission spectrum of the phosphorescent material comprises spectral components in a wavelength region greater than or equal to 500 nm and less than 550 nm,
• wherein a level of the lowest triplet excited state of the host material is lower than a level of the lowest triplet excited state of the first organic compound,
• wherein the first organic compound and the second organic compound are configured to form an exciplex, and
• wherein a peak of an emission spectrum of the exciplex overlaps with an absorption band on the longest wavelength side of the phosphorescent material.

A light-emitting device comprising a pixel portion, the pixel portion comprising:

• a first transistor;
• a second transistor;
• a third transistor;
• a fourth transistor;
• a first light-emitting element electrically connected to the first transistor, the first light-emitting element comprising a first anode, a first light-emitting layer over the first anode, a second light-emitting layer over the first light-emitting layer, and a cathode over the second light-emitting layer;
• a second light-emitting element electrically connected to the second transistor, the second light-emitting element comprising a second anode, the first light-emitting layer over the second anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a third light-emitting element electrically connected to the third transistor, the third light-emitting element comprising a third anode, the first light-emitting layer over the third anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a fourth light-emitting element electrically connected to the fourth transistor, the fourth light-emitting element comprising a fourth anode, the first light-emitting layer over the fourth anode, the second light-emitting layer over the first light-emitting layer, and the cathode over the second light-emitting layer;
• a red color filter under the first anode;
• a green color filter under the second anode;
• and
• a blue color filter under the third anode,
• wherein a color filter is not provided under the fourth anode,
• wherein each of the first transistor, the second transistor, the third transistor, and the fourth transistor comprises an oxide semiconductor,
• wherein each of the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element does not comprise a light-emitting layer between the first light-emitting layer and each of the first anode, the second anode, the third anode, and the fourth anode,
• wherein the first light-emitting layer is separated from the second light-emitting layer,
• wherein the first light-emitting layer comprises a fluorescent material and a host material,
• wherein the second light-emitting layer comprises a phosphorescent material, a first organic compound, and a second organic compound,
• wherein an emission spectrum of the fluorescent material has a peak in a wavelength region of greater than or equal to 420 nm and less than or equal to 480 nm,
• wherein an emission spectrum of the phosphorescent material has a peak in a yellow wavelength region,
• wherein the emission spectrum of the phosphorescent material comprises spectral components in a green wavelength region,
• wherein the emission spectrum of the phosphorescent material comprises spectral components in a wavelength region of greater than or equal to 600 nm and less than or equal to 740 nm,
• wherein a level of the lowest triplet excited state of the host material is lower than a level of the lowest triplet excited state of the first organic compound,
• wherein the first organic compound and the second organic compound are configured to form an exciplex, and
• wherein a peak of an emission spectrum of the exciplex overlaps with an absorption band on the longest wavelength side of the phosphorescent material.