Heterovalent Tin Alloying in Layered MA3Sb2I9 Thin Films: Assessing the Origin of Enhanced Absorption and Self-Stabilizing Charge States

Weis, Andreas; Ganswindt, Patrick; Kaiser, Waldemar; Illner, Hannah; Maheu, Clement; Gluck, Nadja; Dorflinger, Patrick; Armer, Melina; Dyakonov, Vladimir; Hofmann, Jan P.; Mosconi, Edoardo; De Angelis, Filippo und Bein, Thomas (2022): Heterovalent Tin Alloying in Layered MA3Sb2I9 Thin Films: Assessing the Origin of Enhanced Absorption and Self-Stabilizing Charge States. In: Journal of Physical Chemistry C, Bd. 126, Nr. 49: S. 21040-21049

Abstract

Heteroatom alloying of lead-free perovskite derivatives is a highly promising route to tailor their optoelectronic properties and stability for multiple applications. Here, we demonstrate the facile solution-based synthesis of Sn-alloyed layered MA3Sb2I9 thin films by precursor engineering, combining acetate and halide salts. An increasing concentration of tin halides in different oxidation states leads to a strong boost in absorption over the whole visible spectrum. We demonstrate phase-pure synthesis and elucidate the heterovalent incorporation of Sn into the MA3Sb2I9 lattice, proving the formation of additional electronic states in the bandgap by theoretical calculations. On this basis, we dissect the strong absorption increase into three components that we attribute to intervalence and heteroatom-induced interband absorption. Finally, we show the charge-stabilizing effect of the system through robustness toward precursors in mixed oxidation states and trace the improved ambient stability of this material back to this feature.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 1932-7447
• Sprache: Englisch
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 423746744
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 424707803