The color of the light emitted by the second light-emitting unit 8 may be the same as the color of the light emitted by the first light-emitting unit 3 adjacent to the second sub-pixel region 2.

The second light-emitting unit 8 may include a second anode 81 and a second light-emitting layer 82. A second transparent cathode 83 for driving the second light-emitting unit 8 to emit light is disposed on the substrate 10 and located in the second sub-pixel region 2. The orthographic projection of the second transparent cathode on the substrate 10 covers the orthographic projection of the through hole 111 on the substrate 10. The second transparent cathode 83 and the first transparent cathode 33 may be formed in an integrated structure, i.e., disposed in a whole layer, so that they can be fabricated in the same process. A pixel dielectric layer 34 is formed under the first transparent cathode 83, between the first anode 31, the first light-emitting layer 32 of the first sub-pixel region 1 and the first anode 81, the first light-emitting layer 82 of the second sub-pixel region 2.