Structural and functional properties of Al:ZnO thin films grown by Pulsed Laser Deposition at room temperature

Current research on transparent conductive oxides (TCOs) is focusing on indium-free TCOs, such as Al-doped ZnO (AZO), as an alternative to indium-tin oxide. In this work, AZO thin films were grown by Pulsed Laser Deposition at room temperature in oxygen atmosphere. The O₂ pressure was varied from 0.01 Pa to 10 Pa, highlighting the effects of defect formation and oxygen vacancies on the film properties. Structural properties were characterized by X-ray diffraction and Scanning Electron Microscopy, while functional properties were characterized by measurement of electrical conductivity, Hall mobility, carrier density and optical transmission. At an optimal deposition pressure of 2 Pa, optical transparency in the visible range and minimum resistivity (4.5 ? 10^− 4 Ω cm) were found, comparable to state-of-the-art TCOs. Mean value of visible transparency was shown to increase with increasing pressure, up to 88% at a deposition pressure of 10 Pa.