Ink jet printing first and second materials to form a pixel defining layer having groove

1. A method for preparing a pixel defining layer, comprising:

providing a substrate;

forming a first defining pattern on the substrate, said forming the first defining pattern comprising ink jet printing a first material on the substrate, and then forming a concave accommodation groove, the concave accommodation groove constituting the first defining pattern;

forming a second defining pattern by ink jet printing a second material in the concave accommodation groove,

wherein the first defining pattern and the second defining pattern constitute the pixel defining layer.

2. The method according to claim 1 , wherein the concave accommodation groove is formed by ink jet printing the first material to form the first defining pattern layer in a predetermined region of the substrate, and then subjecting the first defining pattern layer to a drying treatment.

3. The method according to claim 2 , wherein the drying treatment includes a vacuum drying treatment under reduced pressure, a normal temperature drying treatment, or a low temperature drying treatment.

4. The method according to claim 3 , wherein,

the vacuum drying treatment under reduced pressure comprises: subjecting the first defining pattern layer to a vacuum drying treatment under reduced pressure by reducing the pressure of a cavity for performing the vacuum drying treatment under reduced pressure to 150 to 250 Pa over 3 to 10 minutes, keeping the reduced pressure for 5 to 15 minutes, and subjecting the first defining pattern layer after vacuum drying treatment under reduced pressure to a baking treatment at a temperature not lower than 200° C.;

the normal temperature drying treatment comprises: allowing the first defining pattern layer stand at a normal temperature for 25 to 50 minutes; and

the low temperature drying treatment comprises: allowing the first defining pattern layer stand at a temperature not higher than 20° C. for 40 to 60 minutes.

5. The method according to claim 1 , wherein the first defining pattern has a first surface energy, and the second defining pattern has a second surface energy, and wherein the first surface energy is higher than the second surface energy.

6. The method according to claim 1 , wherein, before forming the first defining pattern, the method further comprises:

subjecting a surface of the substrate for forming the first defining pattern and the second defining pattern to a modification treatment to reduce the surface energy of the substrate.

7. The method according to claim 1 , wherein the first material comprises at least one of a polyimide and an acrylic material.

8. The method according to claim 1 , wherein said ink jet printing the first material comprises:

dissolving the first material in a first solvent to prepare a first solution and ink jet printing the first solution,

wherein the first material has a concentration of 0.5 wt % to 30 wt % in the first solvent; and

the first solvent has a boiling point not higher than 180° C.

9. The method according to claim 1 , wherein the second defining pattern is formed by

dissolving the second material in a second solvent to prepare a second solution, ink jet printing the second solution containing the second material in the concave accommodation groove, and performing a baking treatment.

10. The method according to claim 9 , wherein the second material comprises at least one of a fluorinated polyimide, a polysiloxane and a fluorinated methyl methacrylate, and

the baking treatment is performed at a temperature not lower than 200° C. and not higher than 250° C.

11. A method for preparing an organic light emitting device (OLED), comprising:

a step of preparing a pixel defining layer, and

a step of forming an organic light emitting layer in the pixel defining layer,

wherein said step of preparing the pixel defining layer is performed by using the method of claim 1 .

12. A pixel defining element, comprising:

a substrate, and

a first defining pattern and a second defining pattern formed on the substrate,

wherein the first defining pattern is composed of a concave accommodation groove formed from a first material, and the second defining pattern is formed from a second material in the concave accommodation groove.

13. The pixel defining element according to claim 12 , wherein the first defining pattern has a first surface energy, and the second defining pattern has a second surface energy, wherein the first surface energy is higher than the second surface energy.

14. The pixel defining element according to claim 12 , wherein the first material comprises at least one of a polyimide and an acrylic material; and

the second material comprises at least one of a fluorinated polyimide, a polysiloxane and a fluorinated methyl methacrylate.

15. The pixel defining element according to claim 13 , wherein the substrate has a third surface energy, wherein the third surface energy is less than the second surface energy.

16. The pixel defining element according to claim 12 , wherein the second defining pattern is a protrusion formed in the concave accommodation groove, wherein a difference in height between a top of the second defining pattern and the concave accommodation groove is not less than 0.5 μm.

17. The pixel defining element according to claim 16 , wherein an upper surface of the second defining pattern is arc-shaped, hemispheric, trapezoidal, or parabolic.

18. The pixel defining element according to claim 12 , wherein the pixel defining layer has a height of 1 to 3 μm, and a width of 15 to 100 μm, and

wherein the concave accommodation groove has a height of 1 to 3 μm, and a width of 15 to 100 μm.

19. An OLED comprising:

the pixel defining element according to claim 12 , and

an organic light emitting layer formed in a pixel region defined by the pixel defining layer.

20. A display device comprising the OLED according to claim 19 .