Method for manufacturing array substrate, and array substrate, display panel and display device

A method for manufacturing an array substrate, comprising:

• forming, on one side of a substrate, a gate electrode layer, a gate insulation layer located on the gate electrode layer and a semiconductor layer located on the gate insulation layer, wherein, the gate electrode layer has a same pattern as the semiconductor layer;
• forming an etching stop layer on the semiconductor layer;
• forming a first through hole, a second through hole and a third through hole in the etching stop layer by patterning the etching stop layer;
• forming a source electrode layer on the etching stop layer and a drain electrode layer on the etching stop layer, wherein the source electrode layer is electrically connected with the semiconductor layer via the first through hole, and the drain electrode layer is electrically connected with the semiconductor layer via the second through hole;
• and
• forming an active layer by etching the semiconductor layer at a location corresponding to the third through hole, wherein the gate electrode layer comprises a first part at the location corresponding to the third through hole and a second part, the second part of the gate electrode layer using a same pattern as the active layer and being different from the first part.