Display substrate with stacked active devices, method for manufacturing the display substrate, and display apparatus comprising the display substrate

A display substrate, comprising:

• a base substrate, and a first transistor layer and a second transistor layer sequentially arranged along a direction away from the base substrate;
• wherein the first transistor layer comprises a first active layer;
• the second transistor layer comprises a second active layer, and at least one insulating layer is arranged between the first active layer and the second active layer;
• the first active layer and the second active layer both are made of low-temperature polysilicon materials;
• the first active layer comprises at least one first channel region and at least one first source-drain doped region;
• the second active layer comprises at least one second channel region and at least one second source-drain doped region;
• an orthographic projection of the at least one second source-drain doped region on the base substrate overlaps with an orthographic projection of the at least one first source-drain doped region on the base substrate;
• and
• the at least one second source-drain doped region is connected to a corresponding first source-drain doped region through a corresponding connecting part filled in a corresponding first via in the at least one insulating layer;
• the display substrate comprises a plurality of pixel units on the base substrate, each of which comprises a light emitting element and a pixel driving circuit for driving the light emitting element;
• the pixel driving circuit comprises:
• a driving transistor configured to output a driving current to the light emitting element according to a gate-source voltage of the driving transistor;
• the pixel driving circuit further comprises a first light emitting control transistor;
• a gate electrode of the first light emitting control transistor is electrically connected to a light emitting control signal line, a first electrode of the first light emitting control transistor is electrically connected to an operating voltage transmission line, and a second electrode of the first light emitting control transistor is electrically connected to a first electrode of the driving transistor;
• and
• the first light emitting control transistor is in the second transistor layer, and a channel region and a source-drain doped region of the first light emitting control transistor are in the second active layer.