Achieving high free electron mobility in ZnO:Al thin films grown by reactive pulsed magnetron sputtering

The study is focused on improvement of the free electron mobility in Al-doped ZnO films grown by cost-effective deposition method of reactive pulsed magnetron sputtering. At optimum growth conditions it yields low absorbing films with Hall effect mobility of 46 cm2V-1s-1, free electron density of 6x1020 cm-3 and electrical resistivity of 2.26x10-4 Ohm cm. The relation between the mobility and free electron density for the films grown at different conditions is discussed in terms of ionized impurity scattering and impurity clustering mechanism or grain boundary limited transport.