Influence of substrate temperature and oxygen partial pressure on the electrical properties of Al-doped ZnO grown by reactive pulsed magnetron sputtering

The study is focused on improvement of the free electron mobility in Al-doped ZnO films grown by reactive pulsed magnetron sputtering. At optimum growth conditions low-absorbing films are obtained with a Hall mobility of 46 cm² V ⁻¹s⁻¹, a free electron density of 6.0x10²⁰ cm⁻³, and an electrical resistivity of 2.26x10⁻⁴ cm. The relation between the mobility and free electron density for different growth conditions is discussed in terms of ionized impurity scattering, impurity clustering, and grain boundary limited transport.