The Tetrel Bond and Tetrel Halide Perovskite Semiconductors

The ion pairs [Cs+ center dot TtX(3)(-)] (Tt = Pb, Sn, Ge; X = I, Br, Cl) are the building blocks of allinorganic cesium tetrel halide perovskites in 3D, CsTtX3, that are widely regarded as blockbuster materials for optoelectronic applications such as in solar cells. The 3D structures consist of an anionic inorganic tetrel halide framework stabilized by the cesium cations (Cs+). We use computational methods to show that the geometrical connectivity between the inorganic monoanions, [TtX(3)(-)](infinity), that leads to the formation of the TtX(6)(4-) octahedra and the 3D inorganic perovskite architecture is the result of the joint effect of polarization and coulombic forces driven by alkali and tetrel bonds. Depending on the nature and temperature phase of these perovskite systems, the Tt . . .X tetrel bonds are either indistinguishable or somehow distinguishable from Tt-X coordinate bonds. The calculation of the potential on the electrostatic surface of the Tt atom in molecular [Cs+ center dot TtX(3)(-)] provides physical insight into why the negative anions [TtX(-)] attract each other when in close proximity, leading to the formation of the CsTtX(3) tetrel halide perovskites in the solid state. The inter-molecular (and inter-ionic) geometries, binding energies, and charge density-based topological properties of sixteen [Cs+ center dot TtX(3)(-)] ion pairs, as well as some selected oligomers [Cs+ center dot PbI3-](n) (n = 2, 3, 4), are discussed.

Automated summary

This article discusses the role of ion pairs [Cs+ center dot TtX(3)(-)] in 3D inorganic cesium tetrel halide perovskites, which are widely used in optoelectronic applications such as solar cells. Computational methods are used to analyze the geometric connectivity between the inorganic monoanions, [TtX(3)(-)], and the formation of the TtX(6)(4-) octahedra and 3D inorganic perovskite architecture. The article also examines the intermolecular geometries, binding energies, and charge density-based topological properties of various ion pairs and oligomers.