A carbon allotrope and a display device including the same are disclosed. The thin-film transistor array substrate, comprising a substrate, a gate electrode on the substrate, an active layer comprising a first active layer, which opposes the gate electrode and is adjacent to the gate electrode thereby comprising a semiconductor material and a plurality of carbon allotropes, and a second active layer, which is in contact with the first active layer and comprises a semiconductor material, a gate insulating film between the gate electrode and the active layer, and a source electrode and a drain electrode respectively in contact with the active layer.