Hafnium oxide (HfO2) thin films were formed by spin coating deposition and annealed in ambient air. Following the molarity optimization of hafnium content in the solution, effect of spin coating and thermal processes on the antireflection properties were analyzed. Characterizations were carried out by spectrophotometer, X-ray diffraction, spectroscopic ellipsometer and scanning electron microscopy measurements. Post deposition annealing temperatures range from 500 to 1000 degrees C. Annealing led the crystallinity of the films above 500 degrees C and possess monoclinic phase. Average reflectivity of 11.32% was achieved with 71.36 nm HfO(2)film after annealing at 700 degrees C. Ellipsometer measurements reveals refractive index of such a film as 1.934 at 600 nm. Average reflectance increases when annealing temperature is over 700 degrees C mainly due to the increase of refractive index which is recorded as 2.05 after annealing at 800 degrees C. Fresnel equations, transfer matrix method and PC1D simulations were carried out for reflectance spectra approximations. The experimental results and the theoretical data were relatively comparable. Spin coating HfO(2)thin films are found promising as an antireflection layer for solar cells.