Electron‐Phonon Coupling Suppression by Enhanced Lattice Rigidity in 2D Perovskite Single Crystals for High‐Performance X‐Ray Detection. Issue 7 (19th December 2022)

• Record Type: Journal Article
• Authors: Zhang, Bobo; Zheng, Tao; You, Jiaxue; Ma, Chuang; Liu, Yucheng; Zhang, Lu; Xi, Jun; Dong, Guohua; Liu, Ming; Liu, Shengzhong (Frank)
• Is Part Of: Advanced materials. Volume 35:Issue 7(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-19
• Subjects: 2D perovskite -- electron‐phonon coupling -- high sensitivity -- lattice rigidity -- X‐ray detection; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202208875
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 2D Dion−Jacobson (DJ) perovskite single crystals (PSCs) usually demonstrate better X‐ray detection performance than Ruddlesden‐Popper (RP) PSCs. However, the mechanism of the improved performance is still elusive. Here, by the aid of strong interactions between dimethylbiguanide (DGA) and PbI2, a novel DJ‐perovskitoid (DGA)PbI4 is designed. From the comparison of (DGA)PbI4 to other 2D PSCs, it is discovered that the tiniest lattice distortion and increased hydrogen bonds in the atom‐scaled analysis strengthen lattice rigidity and weaken electron‐phonon coupling to suppress disordered scattering of carriers, resulting in significantly improved carrier transport and stability. Therefore, high carrier mobility (78.1 cm 2 V −1 s −1 ) and a pronounced sensitivity of 4869.0 µC Gyair −1 cm −2 are achieved using (DGA)PbI4, which are the best in 2D Pb‐based PSC devices to date. Finally, the (DGA)PbI4 devices exhibit good spatial resolution in X‐ray imaging and excellent long‐term stability to work as a promising candidate for medical diagnostics and nondestructive determination. Abstract : A novel 2D perovskite single crystal is designed by introducing a diamine molecule DGA into the lead‐iodine octahedron. Compared with the monoamine o‐F‐PEA, the DGA strongly interacts with the [PbI6 ] 4‐, improving the lattice stiffness, reducing electron‐phonon coupling and lattice distortion, and making the corresponding device to achieve high carrier mobility (78.1 cm 2 V −1 s −1 ) and high X‐ray sensitivity (4869.0 µC Gyair −1 cm −2 ).