An array substrate includes a base substrate; a first thin film transistor on the base substrate and including a first active layer, a first gate electrode, a first source electrode and a first drain electrode; a second thin film transistor on the base substrate and including a second active layer, a second gate electrode, a second source electrode and a second drain electrode; a first gate insulating layer between the first active layer and the first gate electrode; and a second gate insulating layer between the second active layer and the second gate electrode, the second gate insulating layer being different from the first gate insulating layer. The first source electrode, the first drain electrode, and the second gate electrode are in a same layer. The first source electrode and the first drain electrode are on a side of the second gate insulating layer distal to the base substrate.