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

A light-emitting element comprising:

• an anode;
• a cathode;
• a charge generating layer between the anode and the cathode;
• a first light-emitting unit between the anode and the charge generating layer;
• a second light-emitting unit between the cathode and the charge generating layer,
• wherein an emission color of the first light-emitting unit is different from an emission color of the second light-emitting unit,
• wherein the first light-emitting unit comprising:
• a light-emitting layer comprising a first substance having a light-emitting property;
• a first layer between the charge generating layer and the light-emitting layer, the first layer comprising a second substance having an electron transporting property and a third substance having a hole transporting property;
• and
• a second layer between the charge generating layer and the first layer, the second layer comprising a fourth substance having an electron transporting property,
• wherein the second substance is different from the fourth substance.

A light-emitting element comprising:

• an anode;
• a cathode;
• a charge generating layer between the anode and the cathode;
• a first light-emitting unit between the cathode and the charge generating layer;
• a second light-emitting unit between the anode and the charge generating layer,
• wherein an emission color of the first light-emitting unit is different from an emission color of the second light-emitting unit,
• wherein the first light-emitting unit comprising:
• a light-emitting layer comprising a first substance having a light-emitting property;
• a first layer between the charge generating layer and the light-emitting layer, the first layer comprising a second substance having a hole transporting property and a third substance having an electron transporting property;
• and
• a second layer between the charge generating layer and the first layer, the second layer comprising a fourth substance having a hole transporting property,
• wherein the second substance is different from the fourth substance.