Telychko Mykola, Edalatmanesh Shayan, Leng Kai, Abdelwahab Ibrahim, Guo Na, Zhang Chun, Mendieta-Moreno Jesús I, Nachtigall Matyas, Li Jing, Loh Kian Ping, Jelínek Pavel, Lu Jiong
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Institute of Physics, The Czech Academy of Sciences, 162 00 Prague, Czech Republic.
Sci Adv. 2022 Apr 29;8(17):eabj0395. doi: 10.1126/sciadv.abj0395.
Noninvasive imaging of the atomic arrangement in two-dimensional (2D) Ruddlesden-Popper hybrid perovskites (RPPs) is challenging because of the insulating nature and softness of the organic layers. Here, we demonstrate a sub-angstrom resolution imaging of both soft organic layers and inorganic framework in a prototypical 2D lead-halide RPP crystal via combined tip-functionalized scanning tunneling microscopy (STM) and noncontact atomic force microscopy (ncAFM) corroborated by theoretical simulations. STM measurements unveil the atomic reconstruction of the inorganic lead-halide lattice and overall twin-domain composition of the RPP crystal, while ncAFM measurements with a CO-tip enable nonperturbative visualization of the cooperative reordering of surface organic cations driven by their hydrogen bonding interactions with the inorganic lattice. Moreover, such a joint technique also allows for the atomic-scale imaging of the electrostatic potential variation across the twin-domain walls, revealing alternating quasi-1D electron and hole channels at neighboring twin boundaries, which may influence in-plane exciton transport and dissociation.
由于有机层的绝缘性质和柔软性，对二维（2D）Ruddlesden-Popper混合钙钛矿（RPPs）中的原子排列进行非侵入性成像具有挑战性。在这里，我们通过结合尖端功能化扫描隧道显微镜（STM）和非接触原子力显微镜（ncAFM），并辅以理论模拟，展示了在典型的二维卤化铅RPP晶体中对柔软有机层和无机框架的亚埃分辨率成像。STM测量揭示了无机卤化铅晶格的原子重构和RPP晶体的整体孪晶域组成，而使用CO尖端的ncAFM测量能够对由表面有机阳离子与无机晶格的氢键相互作用驱动的协同重排进行无扰动可视化。此外，这种联合技术还允许对孪晶域壁上的静电势变化进行原子尺度成像，揭示相邻孪晶边界处交替的准一维电子和空穴通道，这可能会影响面内激子传输和解离。
