Metal center impact on the high-pressure behaviour of chiral 2D perovskites

The aim of this proposal is the investigation as a function of pressure of the 2D chiral perovskites (R-/S-ClMBA)2SnI4 and (R-/S-ClMBA)2GeI4 (ClMBA= chloromethylbenzylammonium), with the same structural motif of the already HP-PXRD investigated (R-/S-/Rac-ClMBA)2PbI4. Interesting structural and optical features as a function of the central metal have been discovered at ambient pressure, suggesting that evaluating the behaviour at variable pressure would permit further comprehension of the metal role. Moreover, moving away from toxic lead is a current challenge within the field, although only few lead-free chiral perovskites have been reported so far. Our structural experiment will be coupled to the Raman and photoluminescence characterization as a function of pressure, to fully investigate the behaviour of these 2D chiral perovskites upon compression and unveil the evolution of non-linear optical properties with different metal centers.

本研究计划旨在探究2D手性钙钛矿（2D chiral perovskite）(R-/S-ClMBA)₂SnI₄与(R-/S-ClMBA)₂GeI₄（ClMBA=氯甲基苄基铵，chloromethylbenzylammonium）的压力依赖性行为，这两种材料与已通过高压粉末X射线衍射（HP-PXRD）研究的(R-/S-/外消旋-ClMBA)₂PbI₄具有相同的结构基序。在常压下已发现其结构与光学特征随中心金属的变化呈现出有趣的规律，这表明通过研究变压条件下的行为可进一步理解金属的作用机制。此外，摆脱有毒铅的依赖是该领域当前面临的挑战之一，尽管迄今为止报道的无铅手性钙钛矿材料仍较为有限。我们将结合结构实验与压力依赖性拉曼光谱（Raman）及光致发光（photoluminescence）表征，以全面探究这些2D手性钙钛矿在压缩过程中的行为，并揭示不同金属中心下非线性光学性质的演变规律。