Organic light emitting transistor comprising micro-nano grating structure and preparation method thereof

A method of preparing an organic light emitting transistor, comprising:

• providing a base substrate;
• forming an active layer on a side of the base substrate;
• forming a hole transport layer on a side of the active layer away from the base substrate;
• forming a light emitting layer on a side of the hole transport layer away from the base substrate;
• forming an electron transport layer on a side of the light emitting layer away from the base substrate;
• forming at least part of a first micro-nano grating structure on a side of the electron transport layer away from the base substrate;
• and
• forming a first electrode in a region of the electron transport layer provided with the first micro-nano grating structure, wherein at least part of a second micro-nano grating structure is provided on a side of the first electrode away from the base substrate, an orthographic projection of the second micro-nano grating structure on the base substrate is located within an orthographic projection of the first micro-nano grating structure on the base substrate,
• providing a first region and a second region spaced apart on the side of the electron transport layer away from the base substrate, wherein the first micro-nano grating structure is located in the first region, the first electrode is provided on the first micro-nano grating structure, the second region is provided with a third micro-nano grating structure,
• providing a second electrode on the third micro-nano grating structure, wherein a fourth micro-nano grating structure is provided on a side of the second electrode away from the base substrate, an orthographic projection of the fourth micro-nano grating structure on the base substrate is located within an orthographic projection of the third micro-nano grating structure on the base substrate.

A display panel, comprising an organic light emitting transistor, wherein the organic light emitting transistor comprises:

• a base substrate:
• an active layer, provided on a side of the base substrate;
• a hole transport layer, provided on a side of the active layer away from the base substrate;
• a light emitting layer, provided on a side of the hole transport layer away from the base substrate;
• an electron transport layer, provided on a side of the light emitting layer away from the base substrate, wherein at least part of a first micro-nano grating structure is provided on a side of the electron transport layer away from the base substrate;
• a first electrode, provided on the side of the electron transport layer away from the base substrate, wherein at least part of a second micro-nano grating structure is provided on a side of the first electrode away from the base substrate, an orthographic projection of the second micro-nano grating structure on the base substrate is located within an orthographic projection of the first micro-nano grating structure on the base substrate,
• wherein a first region and a second region spaced apart are provided on the side of the electron transport layer away from the base substrate, the first micro-nano grating structure is located in the first region, the first electrode is provided on the first micro-nano grating structure, the second region is provided with a third micro-nano grating structure, the organic light emitting transistor further comprises:
• a second electrode, provided on the third micro-nano grating structure, wherein a fourth micro-nano grating structure is provided on a side of the second electrode away from the base substrate, an orthographic projection of the fourth micro-nano grating structure on the base substrate is located within an orthographic projection of the third micro-nano grating structure on the base substrate.