Dai Hongliang, You Shihai, Ye Huang, Zhu Tingting, Luo Junhua
School of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi, 330022, China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Small. 2023 Nov;19(46):e2304332. doi: 10.1002/smll.202304332. Epub 2023 Jul 18.
The 2D aromatic Dion-Jacobson (DJ) hybrid perovskites combining advantages of high stability, enhanced light absorption, and favorable charge transport, are regarded as a kind of very promising materials for high-performance optoelectronic applications. However, due to the rigidity and large size of the aromatic ring, how to further reduce the interlayer distance to achieve better carrier transport and wider light response window still remain extremely challenging. Here, an interesting DJ-to-ACI (alternating-cations-interaction) reconstruction in 2D aromatic perovskite is first realized by inserting MA cations into (4-AP)PbI (1, 4-AP = 4-amidinopyridinium), successfully constructing an unprecedented ACI perovskite of (4-AP)(MA) Pb I (2, MA = methylamine). Remarkably, such a DJ-to-ACI reconstruction not only effectively reduces the interlayer spacing from 3.89 to 3.15 Å but also alleviates the structural distortion, which jointly causes a significant bandgap narrowing from 2.22 to 1.95 eV (smaller than all current 2D monolayered DJ perovskites), hence achieving a broad photodetection window over 660 nm. This work reports a novel narrow bandgap 2D ACI perovskite derived from the aromatic DJ motif, which sheds light on future regulations on the structure and properties of hybrid perovskites.
二维芳香族狄翁-雅各布森（DJ）杂化钙钛矿结合了高稳定性、增强的光吸收和良好的电荷传输等优点，被认为是一种非常有前途的用于高性能光电器件的材料。然而，由于芳香环的刚性和大尺寸，如何进一步减小层间距离以实现更好的载流子传输和更宽的光响应窗口仍然极具挑战性。在此，通过将甲胺阳离子插入(4-AP)PbI（1, 4-AP = 4-脒基吡啶鎓）中，首次在二维芳香族钙钛矿中实现了一种有趣的从DJ到交替阳离子相互作用（ACI）的重构，成功构建了前所未有的(4-AP)(MA)PbI₂（2, MA = 甲胺）ACI钙钛矿。值得注意的是，这种从DJ到ACI的重构不仅有效地将层间距从3.89 Å减小到3.15 Å，还减轻了结构畸变，这共同导致带隙从2.22 eV显著缩小到1.95 eV（小于所有目前的二维单层DJ钙钛矿），从而实现了超过660 nm的宽光电探测窗口。这项工作报道了一种源自芳香族DJ结构单元的新型窄带隙二维ACI钙钛矿，为未来调控杂化钙钛矿的结构和性能提供了启示。
