Determination of the critical indium composition corresponding to the metal-insulator transition in InxGa1-xN (0.06 ≤ x ≤ 0.135) layers

The low-temperature conductivity of InxGa1-xN alloys (0.06 ≤ x ≤ 0.135) is analyzed as a function of indium composition (x). Although our InxGa1-xN alloys were on the metallic side of the metal-insulator transition, neither the Kubo-Greenwood nor Born approach were able to describe the transport properties of the InxGa1-xN alloys. In addition, all of the InxGa1-xN alloys took place below the Ioeffe-Regel regime with their low conductivities. The observed behavior is discussed in the framework of the scaling theory. With decreasing indium composition, a decrease in thermal activation energy is observed. For the metal-insulator transition, the critical indium composition is obtained as xc = 0.0543 for InxGa1-xN alloys.