A plural semiconductive oxides TFT (sos-TFT) provides improved electrical functionality in terms of charge-carrier mobility and/or threshold voltage variability. The sos-TFT may be used to form a thin film transistor array panel for display devices. An example sos-TFT includes: an insulated gate electrode; a first semiconductive oxide layer having a composition including a first semiconductive oxide; and a second semiconductive oxide layer having a different composition that also includes a semiconductive oxide. The first and second semiconductive oxide layers have respective channel regions that are capacitively influenced by a control voltage applied to the gate electrode. In one embodiment, the second semiconductive oxide layer includes at least one additional element that is not included in the first semiconductive oxide layer where the additional element is one of gallium (Ga), silicon (Si), niobium (Nb), hafnium (Hf), and germanium (Ge).