Display substrate and method for manufacturing the same, and display device

A display substrate, comprising a first display region and a second display region, wherein the display substrate comprises:

• a first base substrate;
• a second base substrate located on a side of the first base substrate;
• a first barrier layer between the first base substrate and the second base substrate;
• and
• a light emitting unit on a side of the second base substrate away from the first base substrate,
• wherein the first base substrate comprises a first through region penetrating the first base substrate, and an orthographic projection of the first through region on the first base substrate is located in an orthographic projection of the first display region on the first base substrate;
• wherein the first barrier layer comprises a second through region penetrating the first barrier layer, and an orthographic projection of the second through region on the first base substrate coincides with the orthographic projection of the first through region on the first base substrate;
• wherein the second base substrate comprises a first substrate sub-portion located in the first display region, the first substrate sub-portion penetrates the second through region, and at least a part of the first substrate sub-portion is located in the first through region, the display substrate comprises a recessed portion, and an orthographic projection of the recessed portion on the first base substrate coincides with the orthographic projection of the first through region on the first base substrate;
• wherein the second base substrate comprises a first surface and a second surface that are located on a side away from the first base substrate, the first surface is located in the first display region, the second surface is located in the second display region, and the first surface and the second surface are formed as a flat surface;
• wherein at least one light emitting unit is arranged in the first display region;
• and
• wherein a plurality of light emitting units are provided in the second display region, and a distribution density of the light emitting units in the first display region is less than a distribution density of the light emitting units in the second display region.