Display substrate and preparation method thereof, and display apparatus

A method for preparing a display substrate, comprising:

• forming a light emitting structure layer on a base substrate, wherein the base substrate has a display area and a peripheral area located at a periphery of the display area, the display area comprises multiple pixel driving circuits connected with the light emitting structure layer in the display area, and the pixel driving circuit comprises a transistor which comprises an active layer located in an interior of the base substrate;
• and
• forming a color filter layer on the light emitting structure layer, wherein the color filter layer comprises a transition structure, the transition structure of the color filter layer is located between the display area and the peripheral area of the base substrate, the transition structure comprises at least one color filter unit, a thickness of the at least one color filter unit decreases in a direction from the peripheral area to the display area, and an overlapping area between an orthographic projection of the transition structure of the color filter layer on the base substrate and the display area of the base substrate is not greater than 5% of the display area;
• wherein there is an overlapping area between the orthographic projection of the transition structure on the base substrate and the display area;
• and forming the color filter layer on the light emitting structure layer comprises:
• forming a first color filter unit, a second color filter unit and a third color filter unit, which are arranged periodically, in the transition structure;
• wherein color filter units in each period are arranged in an order of the first color filter unit, the second color filter unit and the third color filter unit in the direction from the peripheral area to the display area;
• wherein the first color filter unit in each period has a slope having a thickness decreasing in the direction from the peripheral area to the display area, and thicknesses of first color filter units in multiple continuous periods in the direction from the peripheral area to the display area decrease continuously.