Light-emitting element

A light-emitting element comprising:

• a pair of electrodes;
• and
• an EL layer between the pair of electrodes, the EL layer comprising:
• a hole-injection layer;
• a hole-transport layer over the hole-injection layer;
• a light-emitting layer comprising a phosphorescent compound, a first organic compound, and a second organic compound, over the hole-transport layer;
• an electron-transport layer over the light-emitting layer;
• and
• an electron-injection layer over the electron-transport layer,
• wherein the first organic compound and the second organic compound are selected so that an exciplex is formed from the first organic compound and the second organic compound, and
• wherein the ratio of the weight of the phosphorescent compound to the total weight of the first organic compound and the second organic compound is from 0.1% to 2.5%.

A light-emitting element comprising:

• a pair of electrodes;
• a first EL layer;
• a second EL layer;
• and
• a charge-generation layer between the first EL layer and the second EL layer,
• wherein the first EL layer, the second EL layer, and the charge-generation layer are stacked between the pair of electrodes,
• wherein one of the first EL layer and the second EL layer comprises a phosphorescent compound, a first organic compound, and a second organic compound,
• wherein the first organic compound and the second organic compound are selected so that an exciplex is formed from the first organic compound and the second organic compound, and
• wherein the ratio of the weight of the phosphorescent compound to the total weight of the first organic compound and the second organic compound is from 0.1% to 2.5%.