A method for fabricating array substrate, an array substrate and a display device. The method for fabricating the array substrate comprises forming a thin film transistor, a first transparent electrode (14) and a second transparent electrode (19), wherein a multi dimensional electric field is created by the first transparent electrode (17) and the second transparent electrode (19), wherein forming the first transparent electrode (17) comprises: forming a metal oxide film presenting semiconductor properties; forming the first transparent electrode (17) by subjecting a portion of the metal oxide film to metallization treatment, and forming a semiconductor active layer (141) from a portion which is not subjected to the metallization treatment.