Preparation and properties of AZO thin films on different substrates

Al doped ZnO (AZO) films were deposited on glass, polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) at room temperature by radio frequency magnetron sputtering. The structural, surface morphology, electrical and optical properties of the AZO films were characterized by X-ray diffractometry (XRD), atomic force microscopy (AFM), Hall effect measurement and ultraviolet-visible spectrometer, respectively. The films exhibit highly c-axis preferred orientation, and AZO film on glass exhibits compressive stress while that on plastic substrates presents tensile stress. The electrical property of the AZO film on glass is the best among the films on three kinds of substrates. The value of the figure of merit for the AZO film on PEN is much better than that of the AZO film on PET and is close to that of AZO on glass in the wavelength range of 500–900 nm.