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

We have investigated the change in structural and electrical properties of In2xGa2-2xO3 nanowires (x = 1, 0.69 and 0.32) grown with varied indium (In) and gallium (Ga) contents. The as-grown In2xGa2-2xO3 nanowires kept the cubic crystal structure of In2O3 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 In2O3 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 similar to 0.08 degrees. The average threshold voltage values for the In2xGa2-2xO3 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.