Optimization of Zn1-xAlxO film for antireflection coating by RF sputtering

The structural, optical and electrical properties of the Zn1-xAlxO films deposited by RF magnetron sputtering have been investigated. The films of different concentration (x = 0.005, 0.01, 0.02, 0.04) deposited on Si (1 0 0) have been characterized using X-Ray diffraction (XRD), Reflectance and Hall effect measurements. From XRD analysis, it has been inferred that all the films are single crystalline with (0 0 2) preferred orientation and higher Full Width at the Half Maximum (FWHM) for 4 mol.% Al-doped ZnO (i.e., x = 0.04). Reflectance measurement suggests that the optimized concentration of Zn0.96Al0.04O film can be used as an antireflection coating for the solar cell as it exhibits the low reflectivity. The Hall measurements reveal that the electron concentration is found to be increasing with Al concentration and it has been maximum, 7.582 x 1020/cm3 for Zn0.96Al0.04O with low resistivity of 0.0851 Ωcm