Two-dimensional (2D) hybrid perovskites are stoichiometric compounds consisting of alternating inorganic metal-halide sheets and organoammonium cationic layers. This materials class is widely tailorable in composition, structure, and dimensionality and is providing an intriguing playground for the solid-state chemistry and physics communities to uncover structure–property relationships. In this Perspective, we describe semiconducting 2D perovskites containing lead and tin halide inorganic frameworks. In these 2D perovskites, charges are typically confined to the inorganic framework because of strong quantum and dielectric confinement effects, and exciton binding energies are many times greater than kT at room temperature. We describe the role of the heavy atoms in the inorganic framework; the geometry and chemistry of organic cations; and the “softness” of the organic–inorganic lattice on the electronic structure and dynamics of electrons, excitons, and phonons that govern the physical properties of these materials.

中文翻译：

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二维杂化钙钛矿中的电子，激子和声子：连接结构，光学和电子特性

二维（2D）杂化钙钛矿是化学计量的化合物，由交替的无机金属卤化物片和有机铵阳离子层组成。该材料类别在组成，结构和尺寸上可广泛定制，并为固态化学和物理界提供了一个有趣的游乐场，以揭示结构与属性之间的关系。在本《观点》中，我们描述了含有铅和卤化锡无机骨架的半导体二维钙钛矿。在这些2D钙钛矿中，由于强的量子和介电限制效应，电荷通常被限制在无机骨架中，激子结合能比kT大很多倍。在室温下。我们描述了重原子在无机骨架中的作用；有机阳离子的几何形状和化学性质；电子结构的有机-无机晶格的“柔软性”以及控制这些材料物理特性的电子，激子和声子的动力学。