Array substrate and method for manufacturing the same, and display device having photosensitive element, light emitting device and sensing transistor

An array substrate, comprising:

• a base substrate;
• a photosensitive element located between the base substrate and a light emitting device and configured to sense light emitted from the light emitting device and generate a sensing signal according to the light;
• a capacitor configured to store the sensing signal;
• a sensing transistor located between the base substrate and the photosensitive element and configured to transmit the sensing signal to a sensing line, wherein an orthographic projection of the sensing transistor on the base substrate at least partially overlaps with an orthographic projection of the photosensitive element on the base substrate;
• and
• a first dielectric layer covering the sensing transistor,
• wherein the capacitor is located between the photosensitive element and the sensing transistor and comprises a second metal layer, the orthographic projection of the photosensitive element on the base substrate being fully located within an orthographic projection of the second metal layer on the base substrate, and the second metal layer being not comprised in the photosensitive element;
• wherein the capacitor comprises:
• a first metal layer connected to a signal line and located on one side of the first dielectric layer away from the base substrate,
• a second dielectric layer located on the one side of the first dielectric layer away from the base substrate and one side of the first metal layer away from the base substrate, wherein an orthographic projection of the first metal layer on the base substrate is within an orthographic projection of the second dielectric layer on the base substrate, and
• the second metal layer located on one side of the second dielectric layer away from the base substrate and connected to a first electrode of the sensing transistor through a first via penetrating the second dielectric layer and the first dielectric layer;
• wherein the photosensitive element is located on one side of the second metal layer away from the base substrate;
• and
• wherein the sensing transistor comprises:
• an active layer,
• a gate dielectric layer located on one side of the active laver away from the base substrate,
• a gate located on one side of the gas dielectric layer away from the active layer;
• an interlayer dielectric layer located on one side of the gate dielectric layer away from the base substrate and covering the gate, wherein the interlayer dielectric laver defines a second opening and a third opening which extend to the active layer, and
• a second electrode at least partially located in the third opening and in contact with the active layer, wherein the first electrode is at least partially located in the second opening and in contact with the active layer, and wherein a material of the gate is the same as a material of the signal line.