OLED Display Substrate and Display Apparatus

An Organic Light Emitting Diode (OLED) display substrate comprising a base substrate with a display region arranged thereon, wherein first, second and third sub-pixels for respectively displaying different colors are arranged in the display region;

• a first electrode layer, a pixel defining layer, a second electrode layer, and organic functional layers between the first and second electrode layers are arranged in the display region;
• wherein the first electrode layer comprises a plurality of first electrodes respectively arranged in the first, second and third sub-pixels;
• the pixel defining layer is arranged on the first electrode layer and is provided with first, second and third openings for respectively defining the first, second and third sub-pixels;
• surfaces of the first electrodes of the sub-pixels respectively defined by the first, second and third openings towards the second electrode layer are exposed from the first, second and third openings;
• wherein the organic functional layers comprise first, second, and third light-emitting layers;
• the first light-emitting layer covers the display region and is an integral structure, and the second and third light-emitting layers are arranged on a side of the first light-emitting layer towards the second electrode layer;
• wherein the second light-emitting layer comprises a plurality of second sub light-emitting layers;
• an orthographic projection of the second sub light-emitting layers on the base substrate completely covers an orthographic projection of the second opening on the base substrate, and does not overlap with orthographic projections of the first and third openings on the base substrate;
• and
• wherein the third light-emitting layer comprises a plurality of third sub light-emitting layers;
• an orthographic projection of the third sub light-emitting layers on the base substrate completely covers an orthographic projection of the third opening on the base substrate, and does not overlap with orthographic projections of the first and second openings on the base substrate.