Atomic and electronic structure of cesium lead triiodide surfaces.

The (001) surface of the emerging photovoltaic material cesium lead triiodide (CsPbI) is studied. Using first-principles methods, we investigate the atomic and electronic structure of cubic (α) and orthorhombic (γ) CsPbI. For both phases, we find that CsI-termination is more stable than PbI-termination.