Empirical and semi-empirical models are particularly suited to address issues related to complex structures. Based on a general symmetry analysis, herein we build an empirical sp³ tight-binding (TB) model for the reference Pm-3m cubic phase of halide perovskite structures of general formula ABX₃. This TB model includes 16 and 32 basis functions without and with spin orbit coupling (SOC), respectively. The 16 basis functions are made of one "s" and three "p" orbitals for the metal atom B, and the same for three halide atoms X atoms. No basis function is taken into account for the A organic molecule, which position cannot be fixed in the cubic phase. The TB electronic band diagram, with and without SOC of MAPbI₃, is determined based on state of the art density functional theory results that include many body correction (DFT+GW). The band gap is obtained at the R-point with E_g=1.603eV. Close to the band gap, effective masses are: m_h^*=0.215m₀ for the valence band and m_e^*=0.218m0 for the conduction band, which leads to a reduced effective mass of 0.108m₀, all data being consistent with experimental values.

This TB model affords an atomic-scale description to computing various properties, including distorted structures, at a significantly reduced computational cost. The powerfulness of the present TB Hamiltonian is exemplified with the calculation of band-to-band absorption spectra, the variation of the band gap under volumetric strain, as well as the Rashba effect for a uniaxial symmetry breaking. Compared to first-principles approaches, such a semi-empirical model permits us to tackle more difficult issues in terms of size with complex heterostructures, nanostructures or composite materials as well as diversity of physical phenomenon under investigation. It should be as relevant to the future of perovskite device modeling, as it has proved efficient for conventional semiconductors.

This work has been performed within the GOTSOLAR project, which has received funding from the European Union’s Horizon 2020 research and innovation Programme under the grant agreement No 687008. The information and views set out in this abstract are those of the authors and do not necessarily reflect the official opinion of the European Union. Neither the European Union institutions and bodies nor any person acting on their behalf may be held responsible for the use which may be made of the information contained herein.