Structural, electrical and optical characteristics of Al-doped zinc oxide thin films deposited by reactive magnetron sputtering

ZnO:Al (AZO) thin films on glass were deposited by DC reactive magnetron sputtering at approximately 300 degrees C substrate temperature. Structural, electrical and optical properties were investigated as a function of oxygen flow. XRD data shows that AZO thin films are polycrystalline with pronounced c-axis orientation and the grain size increasing with the oxygen flow. The lowest achieved resistivity within the deposited set of samples was 7.6.10(-4) Omega cm. The transmittance of AZO films was above 80 % at 550 nm with the optical band gap between 3.4 and 3.8 eV.