Cover plate and fabricating method thereof, display panel and display device

A cover plate comprising:

• a first substrate;
• a thin film transistor, an optical sensor, and a first electrode on the optical sensor which are sequentially disposed on the first substrate;
• a passivation layer covering the thin film transistor and the first electrode;
• a black matrix disposed on the passivation layer;
• an electrode connection layer disposed on the black matrix, the electrode connection layer comprising an auxiliary cathode and a first electrode connection line which are disposed in a same layer, and the first electrode connection line being connected with the first electrode by a first electrode connection hole penetrating through the passivation layer;
• and
• a planar layer and a second electrode sequentially disposed, the second electrode being connected with the auxiliary cathode by a second electrode connection hole penetrating through the planar layer.

A system, comprising:

• a display panel, wherein the display panel comprises a cover plate comprising:
• a first substrate;
• a thin film transistor, an optical sensor, and a first electrode on the optical sensor which are sequentially disposed on the first substrate;
• a passivation layer covering the thin film transistor and the first electrode;
• a black matrix disposed on the passivation layer;
• an electrode connection layer disposed on the black matrix, the electrode connection layer comprising an auxiliary cathode and a first electrode connection line which are disposed in the same layer, and the first electrode connection line being connected with the first electrode by a first electrode connection hole penetrating through the passivation layer;
• and
• a planar layer and a second electrode sequentially disposed, the second electrode being connected with the auxiliary cathode by a second electrode connection hole penetrating through the planar layer.