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Lee_Preprint.pdf (1.79 MB)
Layer-by-Layer Structural Identification of 2D Ruddlesden-Popper Hybrid Lead Iodide Perovskites by Solid-State NMR Spectroscopy
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
submitted on 07.07.2020 and posted on 08.07.2020by Jeongjae Lee, Woocheol Lee, Keehoon Kang, Takhee Lee, Sung Keun Lee
of two-dimensional (2D) organic-inorganic hybrid halide perovskites for
optoelectronic devices requires detailed understanding of the local
structural features including the Pb-I bonding in the 2D layers and the capping
ligand-perovskite interaction. In this study, we show that 1H and 207Pb
solid-state Nuclear Magnetic Resonance (NMR) spectroscopy can serve as a
non-invasive and complementary technique to quantify the composition and to
probe the local structural features of 2D Ruddlesden-Popper phase BA2MAn-1PbnI3n+1 (n=1-4) with butylammonium (BA) spacers. 207Pb
echo and 1H-detected 207Pb→1H heteronuclear
correlation (HETCOR) experiments enables layer-by-layer structural detection of
2D halide perovskites. We show that the observed correlation between 207Pb
NMR shifts and mean Pb-I bond lengths around each Pb site allows us to probe
the local bonding environment of Pb via its 207Pb NMR shift. We
envisage that this technique will be vital for better understanding the
materials properties as determined by the local atomistic environments in
multi-dimensional halide perovskites.