Light emitting element

A light emitting element comprising:

• a first electrode and a second electrode;
• a first layer and a second layer each containing a P-type semiconductor;
• a third layer containing a light emitting material;
• and
• a fourth layer containing an N-type semiconductor,
• wherein the first layer is in direct contact with the first electrode,
• the second layer is in direct contact with the second electrode,
• the third layer is provided between the first electrode and the second electrode with the first layer and the second layer respectively therebetween, and
• the fourth layer is provided between the third layer and the second layer.

A light emitting element comprising:

• a first electrode over a substrate;
• a first layer generating holes over and in direct contact with the first electrode;
• a third layer containing a light emitting material over the first layer;
• a fourth layer generating electrons over the third layer;
• a second layer generating holes over the fourth layer;
• and
• a second electrode over and in direct contact with the second layer.

A light emitting element comprising:

• a first electrode over a substrate;
• a first layer containing a P-type semiconductor over and in direct contact with the first electrode;
• a third layer containing a light emitting material over the first layer;
• a fourth layer containing an N-type semiconductor over the third layer;
• a second layer containing a P-type semiconductor over the fourth layer;
• and
• a second electrode over and in direct contact with the second layer.