Dion-Jacobson (DJ) hybrid perovskite (HP) single-crystal photodetectors often require operation under external bias due to the centrosymmetric structure of the material, which is not conducive to the intelligence and lightweight of the devices. To solve this problem, the key issue is how to regulate the noncovalent interaction between interlayer diammonium cations and inorganic frameworks to successfully induce polarity. However, there is a lack of research on the relationship between the configuration of diammonium cations and the structure symmetry of DJ HPs. Herein, we successfully constructed a series of polar DJ HPs (1,3-BMACH)PbX₄ (X = Cl, Br, I; 1,3-BMACH is 1,3-bis(aminomethyl)cyclohexane) by changing the configuration of organic cations. It was found that the hydrogen bonding strength between 1,3-BMACH²⁺ cations and the bilateral inorganic framework is different, and it causes the inorganic layer to be more twisted, resulting in a deviation of the positive and negative charge centers in (1,3-BMACH)PbX₄ (X = Cl, Br, I) and successfully inducing polarity. Subsequently, we achieved efficient self-powered X-ray detection in the single-crystal device of (1,3-BMACH)PbBr₄ through polarity-induced bulk photovoltaic effect, which owns outstanding sensitivity (157.3 μC Gy^–1 cm^–2, 0 V bias) and stability under X-ray radiation. Studying the relationship between the configuration of diammonium cations and the crystal structure in DJ HPs can help us design more efficient self-powered optoelectronic devices.

中文翻译：

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调节二铵阳离子的立体异构性构建极性 Dion-Jacobson 杂化钙钛矿用于自供电 X 射线检测


由于材料的中心对称结构，迪昂-雅各布森（DJ）混合钙钛矿（HP）单晶光电探测器往往需要在外部偏压下工作，这不利于器件的智能化和轻量化。为了解决这个问题，关键问题是如何调节层间二铵阳离子与无机骨架之间的非共价相互作用以成功诱导极性。然而，目前缺乏对二铵阳离子构型与DJ HPs结构对称性之间关系的研究。在此，我们成功构建了一系列极性DJ HPs (1,3-BMACH)PbX ₄ (X = Cl, Br, I；1,3-BMACH是1,3-双(氨基甲基)环己烷）通过改变有机阳离子的构型。发现1,3-BMACH ²⁺ 阳离子与双边无机骨架之间的氢键强度不同，导致无机层扭曲较多，导致正负偏差电荷中心位于 (1,3-BMACH)PbX ₄ (X = Cl, Br, I) 并成功诱导极性。随后，我们通过极性诱导的体光伏效应在(1,3-BMACH)PbBr ₄ 单晶器件中实现了高效的自供电X射线检测，该器件具有出色的灵敏度（157.3 μC Gy） ^–1 cm ^–2 ，0 V 偏压）和 X 射线辐射下的稳定性。研究DJ HP中二铵阳离子的构型与晶体结构之间的关系可以帮助我们设计更高效的自供电光电器件。