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arXiv · 1804.06627

Exciton-Dominated Core-Level Absorption Spectra of Hybrid Organic-Inorganic Lead Halide Perovskites

Christian Vorwerk·Claudia Hartmann·Caterina Cocchi·Golnaz Sadoughi·Severin N. Habisreutinger·Roberto Félix·Regan G. Wilks·Henry J. Snaith·Marcus Bär·Claudia Draxl
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Abstract

In a combined theoretical and experimental work, we investigate X-ray Absorption Near-Edge Structure (XANES) spectroscopy of the I $L_3$ and the Pb $M_5$ edges of the methylammonium lead iodide ($\textrm{MAPbI}_3$) hybrid inorganic-organic perovskite and its binary phase $\textrm{PbI}_2$. The absorption onsets are dominated by bound excitons with sizable binding energies of a few hundred meV and pronounced anisotropy. The spectra of both materials exhibit remarkable similarities, suggesting that the fingerprints of core excitations in $\textrm{MAPbI}_3$ are essentially given by its inorganic component, with negligible influence from the organic groups. The theoretical analysis complementing experimental observations provides the conceptual insights required for a full characterization of this complex material.

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Christian Vorwerk, Claudia Hartmann, Caterina Cocchi, Golnaz Sadoughi, Severin N. Habisreutinger, Roberto Félix, Regan G. Wilks, Henry J. Snaith, Marcus Bär, Claudia Draxl. 2018-04-18. Exciton-Dominated Core-Level Absorption Spectra of Hybrid Organic-Inorganic Lead Halide Perovskites. https://doi.org/10.1021/acs.jpclett.8b00378

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