We have studied light randomization and the absorption enhancement in textured ultra-thin AlxGa1-xAs films, with a thickness corresponding to a few optical wavelengths. A correlation between the degree of light randomization and trapping, with the scale length of the texturization geometry was found. The observed absorption enhancement corresponds to 90% of the best possible theoretical value, or 90% light randomization. A modified photon gas model is proposed to calculate the light trapping and absorption at the band edge in the textured thin films.