. . "According to at least some example embodiments, oxide semiconductors may further include Group I elements such as Li and K, Group II elements such as Mg, Ca and Sr, Group III elements such as Ga, Al, In and Y, Group IV elements such as Ti, Zr, Si, Sn and Ge, Group V elements such as Ta, Vb, Nb and Sb, and Ln series elements such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu." . . .