Strain effects on the band gap and optical properties of perovskite SrSnO3 and BaSnO3

We report calculations of the band gaps and optical spectra of perovskite BaSnO3 and SrSnO3 as a function of strain. We find that the behavior of these compounds is controlled almost entirely by the volumetric strain and in particular that unlike commonly studied transition metal based perovskites, there is little sensitivity to strains other than volumetric. The most effective tuning parameters for the gap and optical properties of stannate perovskites are composition (A-site alloying) and volumetric strain.