Manufacturing method of light emitting element

A method for manufacturing a light-emitting element, comprising the steps of:

• forming a hole injecting layer over a first electrode;
• exposing the hole injecting layer to an atmosphere including oxygen;
• forming a light-emitting layer over the hole injecting layer;
• forming an electron transporting layer over the light-emitting layer;
• exposing the electron transporting layer to an atmosphere including oxygen;
• forming a layer for promoting electron injection over the electron transporting layer;
• and
• forming a second electrode over the layer for promoting electron injection after forming the layer for promoting electron injection.

A method for manufacturing a display device, comprising the steps of:

• forming a first electrode over a thin film transistor array substrate;
• forming a light-emitting layer over the first electrode;
• forming an electron transporting layer over the light-emitting layer;
• exposing the electron transporting layer to an atmosphere including oxygen, wherein the processing of exposing to the atmosphere including the oxygen is carried out at a room temperature;
• forming a layer for promoting electron injection over the electron transporting layer;
• and
• forming a second electrode over the layer for promoting electron injection after forming the layer for promoting electron injection.

A method for manufacturing a display device, comprising steps of:

• forming a first electrode over a thin film transistor array substrate;
• forming a hole injecting layer over the first electrode;
• exposing the hole injecting layer to an atmosphere including oxygen;
• forming a light-emitting layer over the hole injecting layer;
• forming an electron transporting layer over the light-emitting layer;
• exposing the electron transporting layer to an atmosphere including oxygen;
• forming a layer for promoting electron injection over the electron transporting layer;
• and
• forming a second electrode over the layer for promoting electron injection after forming the layer for promoting electron injection.