Ellipsometric characterization of random and random-dimer GaAs-Al(x)Ga(1-x)As superlattices

We studied the optical properties of ordered and intentionally disordered GaAs-Al(x)Ga(1-x)As superlattices, with and without dimer-type correlations in the disorder, by means of spectroscopic ellipsometry. The electronic structure of the superlattices has been calculated and compared with the experiments. The optical transitions in ordered, correlated, and uncorrelated disordered superlattices show specific features that we relate to their different electronic structures.