Transparent conductive film (TCO) has been developed rapidly, and reached a climax in recent years due to the development of microelectronics, solar energy and other industries. TCO material is required with not only high optically transmittance (80%) in a wide range of wavelength (300-1000 nm), but also high conductivity, and the resistivity must be less than 1 × 10
-3Ω·cm [
1,
2]. Typical TCO materials include stannic oxide (SnO
2), indium oxide (In
2O
3), gold (Au), palladium (Pd) and zinc oxide (ZnO). However, Au and other metal films absorb too much light accompanied with a low hardness and poor stability, so they have been replaced by metal oxide (SnO
2, In
2O
3 and ZnO) transparent conductive oxide film gradually [
3]. In particular, the most popular TCO, In
2O
3: Sn (ITO) is widely used in booming flat-panel displays, especially large-screen TV. However, there are potential troubles in the future application for the short supply of raw material (0.1 ppm of In
2O
3) and environmentally hazardous (In) [
4,
5]. Al doped ZnO (AZO) film has ever attracted considerable attention in the past three decades due to its unique combination of high transparency and low resistivity [
6-
8]. AZO film has many advantages over ITO films: abundant in raw materials (132 ppm of ZnO), non-toxic, more affordable, and similar property to ITO films. AZO is expected to be the alternative of ITO [
9].