Solid state NMR structural characterization of halide perovskites: the potential contribution of atomistic DFT modeling

Claudio Quarti (1, 2) , Eric Furet (1) , Claudine Katan (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 UMONS - University of Mons [Belgium]

Halide perovskites are a complex class of semiconductors whose structure features two apparently contradictory properties: long-range order associated to the regular crystalline structure,[1] and short-range dynamic disorder, related to the soft nature of the lattice and the libration motion of the organic cations.[2] While the former feature is routinely addressed via X-ray diffraction techniques, the latter requires more local “probes”, with solid state Nuclear Magnetic Resonance (NMR) being an ideal method-of-choice, in light of its sensitivity to local chemical composition and environment, as demonstrated in the recent literature [3-6]. However, the complex line-shapes of solid state NMR measurements, as due to the inherent anisotropic response of this technique, make their interpretation usually a delicate task, hence calling for additional supportive tools. Here we show how periodic DFT simulations can ease the interpretation of the NMR spectroscopic features, providing a complementary perspective to experiments. Targeting nuclei with spin-quantum number I=1/2 for 3D methylammonium lead iodide, bromide and mixed halide systems, we demonstrate the reliability of DFT in reproducing experimental signatures of 13C and 1H light-atoms, with prospects in supporting the characterization of dimensionally confined or hollow perovskite architectures, where the organic component has more important structural/templating role. Quantitative prediction of 207Pb nuclei is more challenging but the different response from pure phase iodide and bromide lead perovskites is well reproduced by DFT simulations. This motivated us to investigate on mixed halide compositions, confirming the sensitivity of NMR to the halide composition,[6-7] and segregation, already at the scale of the individual PbX6 octahedron.[8] Our results open the prospect for joint theoretical-experimental investigations of halide perovskite materials, that combine solid state NMR and periodic DFT simulations. [1] Weller, M. T.; Weber, O. J.; Frost, J. M.; Walsh, A. Cubic Perovskite Structure of Black Formamidinium Lead Iodide, α‐[HC(NH2)2]PbI3, at 298 K, J. Phys. Chem. Lett. 2015, 6, 3209-3212. [2] Quarti, C.; Mosconi, E.; De Angelis, F. Structural and electronic properties of organo-halide hybrid perovskites from ab initio molecular dynamics, Phys. Chem. Chem. Phys., 2015, 17, 9394-9409. [3] Piveteau, L.; Morad, V.; Kovalenko, M. V. Solid-State NMR and NQR spectroscopy of lead-halide perovskite materials, J. Am. Chem. Soc. 2020, 142, 19413-19437. [4] Kubicki, D. J.; Prochowicz, D.; Hofstetter, A.; Zakeeruddin, S. M.; Grätzel, M.; Emsley, L.; Phase Segregation in Cs‐, Rb- and K‐Doped Mixed-Cation (MA)x(FA)1−xPbI3 Hybrid Perovskites from Solid-State NMR’, J. Am. Chem. Soc. 2017, 139, 14173–14180. [5] Milic, J. V.; Im, J.-H.; Kubicki, D. J.; Ummadisingu, A.; Seo, J.-Y.; Li, Y. Ruiz-Preciado, M. A.; Ibrahim Bar, M.; Zakeeruddin, S. M.; Emsley, L.; Grätzel, M. Supramolecular Engineering for Formamidinium-Based Layered 2D Perovskite Solar Cells: Structural Complexity and Dynamics Revealed by Solid-State NMR Spectroscopy, Adv. Energy Mater. 2019, 9, 1900284. [6] Rosales, B. A.; Men, L.; Cady, S.; Hanrahan, M. P.; Rossini, A. J.; Vela, J. Persistent Dopants and Phase Segregation in Organolead Mixed- Halide Perovskites, Chem. Mater. 2016, 28, 6848–6859. [7] Roiland, C.; Trippé-Allard, G.; Jemli, K.; Alonso, B.; Ameline, J.-C.; Gautier, R.; Bataille, T.; Le Pollès, L.; Deleporte, E.; Even, J.; Katan, C. Multinuclear NMR as a tool for studying local order and dynamics in CH3NH3PbX3 (X = Cl, Br, I) hybrid perovskites, Phys. Chem. Chem. Phys. 2016, 18, 27133–27142. [8] Quarti C., Furet E., Katan C., DFT simulations as valuable tool to support NMR characterization of halide perovskites: the case of pure and mixed halide perovskites, submitted under invitation to Helvetica Chimica Acta Acknowledgements This work has been supported by Agence Nationale de la Recherche, project ANR-18-CE05-0026 (MORELESS).

Domaines: Chimie théorique et/ou physique

Claudio Quarti, Eric Furet, Claudine Katan. Solid state NMR structural characterization of halide perovskites: the potential contribution of atomistic DFT modeling. Atomic-level characterization of hybrid perovskites (HPATOM), Jan 2021, Online, France. ⟨hal-03124514⟩