CROSS REFERENCE TO RELATED APPLICATION(S) APPLICATIONS

The present application is a 35 U.S.C. 371 national stage application of the PCT international Application No. PCT/CN2019/081463 filed on Apr. 4, 2019, which claims the benefit of Chinese Patent Application No. 201810438219.8 filed on May 9, 2018, the entire disclosures of both are incorporated herein by reference.

TECHNICAL FIELD

The present application relates to the field of display technologies, and in particular to a display substrate, a manufacturing method thereof and a display device.

BACKGROUND ART

With the development of display technologies, Organic Light-Emitting Diode (OLED) display substrates have been widely used.

An OLED display substrate usually comprises a base plate and a plurality of OLEDs arranged on the base plate. Besides, a color resist layer is further disposed on a side of the plurality of OLEDs away from the base plate. Exemplarily, such OLEDs can all emit white light. The color resist layer comprises a plurality of color resist blocks corresponding to the plurality of OLEDs respectively. Specifically, the plurality of color resist blocks comprise red color resist blocks, green color resist blocks and blue color resist blocks. Each color resist block only allows transmission of light having a designated wavelength among the incident white light. For example, the red color resist block only allows transmission of red light, the green color resist block only allows transmission of green light, and the blue color resist block only allows transmission of blue light, such that the OLED display substrate emits colored light.

However, in related arts, the colored light emitted from the OLED display substrate has a lower color purity, which results in a poor display effect of the OLED display substrate.

SUMMARY

According to an aspect of the present disclosure, a display substrate is provided. The display substrate comprises: a base plate, a plurality of pixel structures on the base plate, and a color resist layer on a side of the plurality of pixel structures away from the base plate, wherein the color resist layer comprises a plurality of color resist blocks, each color resist block corresponding to one or more of the plurality of pixel structures, and light emitted from each of the plurality of pixel structures has the same color as the color resist block corresponding thereto.

Optionally, each pixel structure comprises a plurality of electroluminescent structures connected in series.

Optionally, each pixel structure comprises a first light emitting layer, a second light emitting layer, a first electrical connection layer and a third light emitting layer arranged on the base plate sequentially. The plurality of electroluminescent structures comprises a first electroluminescent structure and a second electroluminescent structure. The first electroluminescent structure comprises the first light emitting layer and the second light emitting layer. The second electroluminescent structure comprises the third light emitting layer. The first electroluminescent structure and the second electroluminescent structure are connected in series via the first electrical connection layer. As an example, the first light emitting layer comprises a red light emitting layer, the second light emitting layer comprises a green light emitting layer, and the third light emitting layer comprises a blue light emitting layer.

Optionally, each pixel structure comprises a first light emitting layer, a second electrical connection layer, a second light emitting layer, a first electrical connection layer and a third light emitting layer arranged on the base plate sequentially. The plurality of electroluminescent structures comprises a first electroluminescent structure, a second electroluminescent structure and a third electroluminescent structure. The first electroluminescent structure comprises the first light emitting layer, the second electroluminescent structure comprises the second light emitting layer, and the third electroluminescent structure comprises the third light emitting layer. The first electroluminescent structure and the second electroluminescent structure are connected in series via the second electrical connection layer. The second electroluminescent structure and the third electroluminescent structure are connected in series via the first electrical connection layer.

Optionally, each color resist block corresponds to a respective pixel structure of the plurality of pixel structures.

Optionally, each pixel structure further comprises a first electrode and a second electrode, wherein the first electrode, the plurality of electroluminescent structures and the second electrode are arranged on the base plate sequentially. The first electrode comprises a reflective conducting layer, and the second electrode comprises a transflective conducting layer. A wavelength of light emitted from the pixel structure is positively correlated with a distance between the reflective conducting layer and the transflective conducting layer.

Optionally, the first electrode further comprises a first transparent conducting layer, an insulating layer and a second transparent conducting layer, wherein the first transparent conducting layer, the reflective conducting layer, the insulating layer and the second transparent conducting layer are arranged on the base plate sequentially. The second transparent conducting layer is electrically connected with the reflective conducting layer by means of a via hole in the insulating layer, and a wavelength of light emitted from the pixel structure is positively correlated with a thickness of the insulating layer in the first electrode.

Optionally, the first electrode further comprises a first transparent conducting layer and a second transparent conducting layer, wherein the first transparent conducting layer, the reflective conducting layer and the second transparent conducting layer are arranged on the base plate sequentially, and a wavelength of light emitted from the pixel structure is positively correlated with a thickness of the second transparent conducting layer in the first electrode.

Optionally, each pixel structure further comprises a functional film located between the first electrode and the second electrode, wherein the functional film comprises at least one of an electron injection layer, an electron transport layer, a hole injection layer and a hole transport layer, and a wavelength of light emitted from the pixel structure is positively correlated with a thickness of the functional film in the pixel structure.

Optionally, a distance d between the reflective conducting layer and the transflective conducting layer satisfies

d=k⁢λ2⁢n⁢cos⁢θ,

wherein, k is a coefficient being positive integer, λ is a wavelength of light emitted from the pixel structure, n is an average refractive index of a medium between the reflective conducting layer and the transflective conducting layer, and θ is a reflective angle of light emitted from the pixel structure on the reflective conducting layer.

Optionally, the plurality of pixel structures comprises a first pixel structure for emitting a first color of light, a second pixel structure for emitting a second color of light, and a third pixel structure for emitting a third color of light. The coefficients k keeps the same in the first pixel structure, the second pixel structure and the third pixel structure.

Optionally, the plurality of pixel structures comprises a first pixel structure for emitting a first color of light, a second pixel structure for emitting a second color of light, and a third pixel structure for emitting a third color of light. The coefficients k keeps the same in the first pixel structure and the second pixel structure, but being smaller by one than the coefficient k in the third pixel structure.

According to another aspect of the present disclosure, a manufacturing method for a display substrate is provided. The method comprises steps of: providing a base plate; forming a plurality of pixel structures on the base plate; and forming a color resist layer on a side of the plurality of pixel structures away from the base plate. The color resist layer comprises a plurality of color resist blocks, each color resist block corresponding to one or more of the plurality of pixel structures, and light emitted from each of the plurality of pixel structures has the same color as the color resist block corresponding thereto.

Optionally, the step of forming a plurality of pixel structures on the base plate comprises: for each pixel structure, forming a first electroluminescent structure, a first electrical connection layer and a second electroluminescent structure sequentially on the base plate, wherein the first electroluminescent structure comprises a first light emitting layer and a second light emitting layer, the second electroluminescent structure comprises a third light emitting layer, and the first electroluminescent structure and the second electroluminescent structure are connected in series via the first electrical connection layer. As an example, the first light emitting layer comprises a red light emitting layer, the second light emitting layer comprises a green light emitting layer, and the third light emitting layer comprises a blue light emitting layer.

Optionally, the step of forming a plurality of pixel structures on the base plate comprises: for each pixel structure, forming a first electroluminescent structure, a second electrical connection layer, a second electroluminescent structure, a first electrical connection layer and a third electroluminescent structure sequentially on the base plate, wherein the first electroluminescent structure comprises a first light emitting layer, the second electroluminescent structure comprises a second light emitting layer, and the third electroluminescent structure comprises a third light emitting layer. Further, the first electroluminescent structure and the second electroluminescent structure are connected in series via the second electrical connection layer, and the second electroluminescent structure and the third electroluminescent structure are connected in series via the first electrical connection layer.

According to yet another aspect of the present disclosure, a display device is provided, wherein the display device comprises a display substrate as described in any of the above embodiments.

