Two-dimensional (2D) perovskite broadband emitters are gaining intensive attention in light-emitting fields. However, the limitation of structure distortion modulation hinders the increase of emission intensity, and the high toxicity of organic diamine causes potential damage to human health. Herein, we utilize a green organic spacer 5-ammonium valeric acid (Ava) to template novel 2D lead chloride hybrids, Ava₂PbCl₄, where intermolecular O1···H–O2 interactions form between the adjacent organic cation layers. The intermolecular hydrogen bonding in Ava₂PbCl₄ causes a larger cation penetration depth which enables larger structural deformation than the pentamethylenediammonium lead chloride (PDAPbCl₄) reference. This octahedral deformation further leads to ultrabroadband emission in Ava₂PbCl₄, which achieves enhanced photoluminescence quantum yield (2.83%) compared to PDAPbCl₄ (0.4%). Further mechanism investigation indicates that these broadband emissions could be assigned as the transient self-trapped excitons luminescence. Density functional theory calculation indicates that the octahedral distortions are traced to an electronic origin as well. The above findings reveal the key role of intermolecular hydrogen bonding in modulating the photophysical properties of 2D perovskites and will benefit the design of green perovskites for optoelectronic applications.

中文翻译：

---

5-戊酸铵模板化氯化铅钙钛矿中的分子间氢键相关结构畸变和宽带白光发射

二维 (2D) 钙钛矿宽带发射器在发光领域受到广泛关注。然而，结构畸变调制的局限性阻碍了发射强度的增加，有机二胺的高毒性对人体健康造成潜在危害。在此，我们利用绿色有机间隔基 5-戊酸铵 (Ava) 来模板化新型 2D 氯化铅杂化物 Ava ₂ PbCl ₄，其中相邻有机阳离子层之间形成分子间 O1...H-O2 相互作用。Ava ₂ PbCl _{4 中}的分子间氢键导致更大的阳离子渗透深度，这使得结构变形比五亚甲基二铵氯化铅 (PDAPbCl ₄） 参考。这种八面体变形进一步导致 Ava ₂ PbCl ₄中的超宽带发射，与 PDAPbCl ₄ (0.4%)相比，其实现了增强的光致发光量子产率 (2.83 %)。进一步的机制研究表明，这些宽带发射可以被指定为瞬态自陷激子发光。密度泛函理论计算表明八面体畸变也可以追溯到电子起源。上述发现揭示了分子间氢键在调节二维钙钛矿光物理性质中的关键作用，并将有利于光电应用中绿色钙钛矿的设计。