Study on ZnO : Al (ZAO) films by DC reaction magnetron sputtering

The high quality ZnO:Al films were successfully produced by DC reaction mag netron sputtering technology. The Al-doping effect on electrical and optica l properties and its scattering mechanism are discussed in detail. The anal yses of X-ray diffractometer (XRD), X-ray photoelectron spectroscopy(XPS) a nd high resolution Auger electron spectroscopy (AES) show that Al2O3 could be effectively removed by controlling oxygen now and Al-doping concentratio n during deposition of ZnO:AI films. Zn, Al and oxygen elements are well di stributed through the films. For highly degenerated ZnO:Al semi-conductive thin films, the theoretical and experimental results reveal that the ionize d impurity scattering dominates the Hall mobility in the films in the low-t emperature range, while the lattice vibration scattering becomes a major sc attering mechanism in the high-temperature range. The grain boundary scatte ring only plays a major role in the ZAO films with small grain size las com pared to the electron mean free path). The photoelectric properties of ZAO films show that it has low resistivity ( similar to 5 x 10(-4) Omega cm), a nd the transmittance in visible range and the reflectance in IR region are above 80% and 60%, respectively.