A method for fabricating a display device includes forming a thin film transistor on a base substrate, forming a first electrode connected to the thin film transistor, forming a pixel defining layer overlapping a portion of the first electrode, such that the pixel defining layer exposes a portion of the first electrode and partitions pixel areas, forming a block copolymer layer on the first electrode and the pixel defining layer, patterning the block copolymer layer, etching the pixel defining layer by using the patterned block copolymer layer as a mask, such that an uneven pixel defining layer with a plurality of defining layer grooves is formed, and forming a light emitting layer on the first electrode and the uneven pixel defining layer.