an array substrate, a method of manufacturing the array substrate, and a display device are provided. The array substrate includes: a base substrate; a first thin film transistor and a second thin film transistor on the base substrate, wherein the first thin film transistor comprises a first active layer, the second thin film transistor comprises a second active layer, and the second active layer is on a side of the first active layer away from the base substrate; and an interlayer dielectric layer and a first buffer layer between the first active layer and the second active layer, wherein the interlayer dielectric layer is capable of supplying hydrogen and the first buffer layer is capable of blocking hydrogen.