OLED display panel with black pixel defining layer and flat layer

An organic light emitting display (OLED) display panel, comprising a plurality of sub-pixels arranged in an array, wherein each of the sub-pixels comprises a base substrate, a thin-film transistor (TFT) layer disposed on the base substrate, a flat layer disposed on the TFT layer, a first electrode disposed on the flat layer, a pixel defining layer disposed on the first electrode and the flat layer, a light emitting layer disposed on the first electrode, a transparent second electrode disposed on the light emitting layer and the pixel defining layer, and an encapsulation layer disposed on the second electrode;

• and
• a portion of at least one of the flat layer and the pixel defining layer is formed by a black shielding material;
• wherein each of the sub-pixels has a transparent area and a non-transparent area arranged in turn, and the first electrode and the light emitting layer are located in the non-transparent area;
• wherein the flat layer is disposed above the non-transparent area, and the pixel defining layer is simultaneously disposed above the non-transparent area and the transparent area, the flat layer is formed by the black shielding material, and the pixel defining layer is formed by a transparent material.