Resolving atomic structure of 2D Ruddlesden-Popper hybrid perovskites 

We demonstrate a sub-angstrom resolution imaging of both soft organic layers and inorganic framework in a prototypical 2D lead-halide Ruddlesden-Popper hybrid perovskites 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.

M. Telychko, Sh. Edalatmanesh, K. Leng, I. Abdelwahab, N. Guo, Ch. Zhang, J.I. Mendieta-Moreno, M. Nachtigall, J. Li, K.P. Loh, P. Jelínek, J. Lu
Sub-angstrom noninvasive imaging of atomic arrangement in 2D hybrid perovskites
Science Advances 8 (2022) eabj0395(1) - eabj0395(8).