Effect of argon deposition pressure on the properties of aluminium-doped ZnO films deposited layer-by-layer using magnetron sputtering

ZnO:Al films are deposited layer-by-layer onto silicon and glass substrates, by using the radiofrequency magnetron sputtering method at various argon pressures from 0.5 to 2 Pa in a deposition chamber. The influence of this pressure on the structure and the optical and electrical properties of ZnO:Al films is studied. Higher argon pressures are found to reduce the electron mobility in transparent conductive ZnO:Al films and to worsen their conducting properties owing to the free electron scattering by grain boundaries. An increase in the free electron scattering at higher argon pressures reduces the transparency of ZnO:Al films in the visible spectral range