Organic–inorganic hybrid ferroelectrics have attracted considerable attention due to their outstanding piezoelectricity, mechanical flexibility, and robust nonlinear optical properties. But the species with above room-temperature (RT) ferroelectricity, visible-light bandgap, and high photoelectric performance are still scarce. Herein, a novel organic–inorganic hybrid ferroelectric [C₄N₂H₁₄]₂[Sb₂I₁₀] has been synthesized hydrothermally and employed as a light-absorbing layer in organic–inorganic hybrid solar cells. A polar monoclinic structure with a space group of Pn was resolved by single-crystal XRD. A direct band gap of 1.89 eV was revealed in [C₄N₂H₁₄]₂[Sb₂I₁₀] by UV–vis spectroscopy and density functional theory (DFT) studies. A dramatic enhancement in photoelectric performance has been achieved by turning the ferroelectric polarization, leading to a maximum V_oc ∼ 0.52 V and J_sc ∼ 15.52 μA/cm², which are 15-fold and 29-fold higher than those of the unpoled sample, respectively. This work may open new avenues for the application of molecular ferroelectrics in optoelectronic devices.

中文翻译：

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高温分子铁电 [C4N2H14]2[Sb2I10]，具有窄带隙和可切换光电响应


有机-无机杂化铁电体因其出色的压电性、机械柔韧性和强大的非线性光学特性而引起了相当大的关注。但是，具有室温 （RT） 以上铁电性、可见光带隙和高光电性能的物种仍然稀缺。在此，已经通过水热法合成了一种新型有机-无机杂化铁电体 [C₄N₂H₁₄]₂[Sb₂I₁₀]，并用作有机-无机混合太阳能电池中的光吸收层。通过单晶 XRD 解析了空间群为 Pn 的极性单斜晶结构。通过紫外-可见光谱和密度泛函理论 （DFT） 研究，[C₄N₂H₁₄]₂[Sb₂I₁₀] 的直接带隙为 1.89 eV。通过转动铁电极化，光电性能得到了显著增强，导致最大 V_oc ∼ 0.52 V 和 J_sc ∼ 15.52 μA/cm²，分别比未极化样品高 15 倍和 29 倍。这项工作可能为分子铁电体在光电器件中的应用开辟新的途径。