The effect of Ga content on In₂xGa₂-₂xO₃ nanowire transistor characteristics

We have investigated the change in structural and electrical properties of In(2x)Ga(2-2x)O(3) nanowires (x = 1, 0.69 and 0.32) grown with varied indium (In) and gallium (Ga) contents. The as-grown In(2x)Ga(2-2x)O(3) nanowires kept the cubic crystal structure of In(2)O(3) intact even when the atomic percentages of Ga were increased to 31% (x = 0.69) and 68% (x = 0.32) in comparison to the total amount of In and Ga. However, as Ga added to In(2)O(3) structure was substituted with In, the lattice constant decreased and, consequently, the main peaks observed in x-ray diffraction in the direction of (222), (400) and (440) shifted by around ∼0.08°. The average threshold voltage values for the In(2x)Ga(2-2x)O(3) nanowire transistors were -9.9 V (x = 1), -6.6 V (x = 0.67) and -5.6 V (x = 0.32), exhibiting a more positive shift and the sub-threshold slope increased to 0.53 V /dec (x = 1), 0.33 V /dec (x = 0.67) and 0.27 V /dec (x = 0.32), showing an improved switching characteristic with increasing Ga.