Maufort Arthur, Cerdá Jesús, Van Hecke Kristof, Deduytsche Davy, Verding Arne, Ruttens Bart, Li Wei, Detavernier Christophe, Lutsen Laurence, Quarti Claudio, Vanderzande Dirk, Beljonne David, Van Gompel Wouter T M
Hybrid Materials Design, Institute for Materials Research (imo-imomec), Hasselt University, Martelarenlaan 42, B-3500 Hasselt, Belgium.
Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
Inorg Chem. 2024 Mar 25;63(12):5568-5579. doi: 10.1021/acs.inorgchem.3c04536. Epub 2024 Mar 12.
Two-dimensional (2D) hybrid organic-inorganic perovskites constitute a versatile class of materials applied to a variety of optoelectronic devices. These materials are composed of alternating layers of inorganic lead halide octahedra and organic ammonium cations. Most perovskite research studies so far have focused on organic sublattices based on phenethylammonium and alkylammonium cations, which are packed by van der Waals cohesive forces. Here, we report a more complex organic sublattice containing benzotriazole-based ammonium cations packed through interdigitated π-π stacking and hydrogen bonding. Single crystals and thin films of four perovskite derivatives are studied in depth with optical spectroscopy and X-ray diffraction, supported by density-functional theory calculations. We quantify the lattice stabilization of interdigitation, dipole-dipole interactions, and inter- as well as intramolecular hydrogen bonding. Furthermore, we investigate the driving force behind interdigitation by defining a steric occupancy factor σ and tuning the composition of the organic and inorganic sublattice. We relate the phenomenon of interdigitation to the available lattice space and to weakened hydrogen bonding to the inorganic octahedra. Finally, we find that the stabilizing interactions in the organic sublattice slightly improve the thermal stability of the perovskite. This work sheds light on the design rules and structure-property relationships of 2D layered hybrid perovskites.
二维（2D）有机-无机杂化钙钛矿是一类应用于多种光电器件的多功能材料。这些材料由无机卤化铅八面体和有机铵阳离子的交替层组成。到目前为止，大多数钙钛矿研究都集中在基于苯乙铵和烷基铵阳离子的有机亚晶格上，它们通过范德华内聚力堆积。在此，我们报道了一种更复杂的有机亚晶格，其包含通过叉指状π-π堆积和氢键堆积的基于苯并三唑的铵阳离子。利用光谱学和X射线衍射对四种钙钛矿衍生物的单晶和薄膜进行了深入研究，并得到了密度泛函理论计算的支持。我们量化了叉指化、偶极-偶极相互作用以及分子间和分子内氢键的晶格稳定性。此外，我们通过定义空间占有率因子σ并调整有机和无机亚晶格的组成，研究了叉指化背后的驱动力。我们将叉指化现象与可用晶格空间以及与无机八面体减弱的氢键联系起来。最后，我们发现有机亚晶格中的稳定相互作用略微提高了钙钛矿的热稳定性。这项工作揭示了二维层状杂化钙钛矿的设计规则和结构-性能关系。
