Display substrate, manufacturing method thereof, and display device

A display substrate, comprising:

• a base substrate at least comprising a pixel area and a hole area;
• a plurality of sub-pixels on the base substrate, wherein the plurality of sub-pixels are located in the pixel area;
• a hole in the hole area;
• a first barrier dam arranged between the sub-pixels and the hole and at least partially surrounding the hole;
• a second barrier dam on a side of the first barrier dam away from the hole;
• an organic material layer comprising at least one film layer, wherein an orthographic projection of the organic material layer on the base substrate falls within the pixel area;
• a filling structure, wherein at least a portion of the filling structure is arranged between the hole and the first barrier dam;
• and
• a functional film layer arranged on a side of the organic material layer close to the base substrate,
• wherein the filling structure and the at least one film layer of the organic material layer are located in the same layer and comprise the same material;
• wherein an orthographic projection of the first barrier dam on the base substrate has a width smaller than that of an orthographic projection of the second barrier dam on the base substrate;
• wherein the functional film layer comprises:
• a first conductive layer on the base substrate;
• a gate insulating layer on a side of the first conductive layer away from the base substrate;
• a second conductive layer on a side of the gate insulating layer away from the base substrate;
• an interlayer dielectric layer on a side of the second conductive layer away from the base substrate;
• a third conductive layer on a side of the interlayer dielectric layer away from the base substrate;
• and
• a passivation layer on a side of the third conductive layer away from the base substrate;
• and
• wherein the first barrier dam comprises a stacked layer structure, the stacked layer structure comprising portions which are respectively located in the first conductive layer, the gate insulating layer, the second conductive layer, the interlayer dielectric layer, the third conductive layer and the passivation layer;
• and the passivation layer comprises a first portion located in the first barrier dam, the third conductive layer comprises a first portion located in the first barrier dam, and an orthographic projection of the first portion of the passivation layer on the base substrate falls within an orthographic projection of the first portion of the third conductive layer on the base substrate.