The present disclosure relates to a photodiode, a method for preparing the same, and an electronic device. The photodiode includes: a first electrode layer and a semiconductor structure that are stacked, a surface of the semiconductor structure away from the first electrode layer having a first concave-convex structure; and a second electrode layer arranged on a surface of the semiconductor structure away from the first electrode layer, a surface of the second electrode layer away from the first electrode layer having a second concave-convex structure.