One-dimensional metal halides with edge-sharing octahedra at high pressure*

Halide perovskites represent an extensive family of materials with chemical and structural versatility and display remarkable optical and electronic properties that find applications for a wide range of technologies. The structural tunability of halide perovskites is also reflected in the ability to derive a wide variety of related, low-dimensional halide perovskites and analogous systems. Here I will focus on two examples where lattice compression is used to modulate the electronic structures and search for intriguing electronic states in one-dimensional metal halides with edge-sharing octahedra. i) We demonstrate that rare electron-electron interaction enhanced by Cs-mediated electron redistribution plays a direct and prominent role in the low-temperature electrical transport of compressed δ-CsPbI₃ and renders Fermi liquid-like behavior [1]. ii) We demonstrate pressure induces a highly anisotropic electronic structure and quasi-one-dimensional metallicity in δ-CsSnI₃ [2]. These studies present a promising high-pressure strategy for tuning the electronic structures and achieving diverse electronic states in the broad family of low-dimensional metal halides.