Computed electronic and optical properties of SnO2 under compressive stress

Miglio, Anna [UCL] Saniz, R. [CMT-group, Department Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen] Waroquiers, David [UCL] Stankovski, Martin [UCL] Giantomassi, Matteo [UCL] Hautier, Geoffroy [UCL] Rignanese, Gian-Marco [UCL] Gonze, Xavier [UCL]

We consider the effects of three different types of applied compressive stress on the structural, electronic and optical properties of rutile SnO2. We use standard density functional theory (DFT) to determine the structural parameters. The effective masses and the electronic band gap, as well as their stress derivatives, are computed within both DFT and many-body perturbation theory (MBPT). The stress derivatives for the SnO2 direct band gap are determined to be 62, 38 and 25 meV/GPa within MBPT for applied hydrostatic, biaxial and uniaxial stress, respectively. Compared to DFT, this is a clear improvement with respect to available experimental data. We also estimate the exciton binding energies and their stress coefficients and compute the absorption spectrum by solving the Bethe–Salpeter equation.