Narrow-Linewidth Emission and Weak Exciton-Phonon Coupling in 2D Layered Germanium Halide Perovskites
© 2025 Wiley‐VCH GmbH.
| Publié dans: | Advanced materials (Deerfield Beach, Fla.). - 1998. - (2025) vom: 28. Apr., Seite e2419879 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2025
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| Accès à la collection: | Advanced materials (Deerfield Beach, Fla.) |
| Sujets: | Journal Article germanium halide perovskites lead‐free perovskites light‐emitting materials metal halide semiconductors optoelectronics photophysics |
| Résumé: | © 2025 Wiley‐VCH GmbH. The photophysical properties of low-dimensional metal-halide semiconductors and their tunability make them promising candidates for light-absorbing and emitting applications. Yet, the germanium-based halide perovskites to date lack desirable light-emitting properties, with so far only very broad, weak, and unstructured photoluminescence (PL) reported due to significant octahedral distortion. Here, the photophysical properties of the 2D layered Ruddlesden-Popper semiconductors (4F-PMA)2GeI4 and (4F-PMA)2PbI4 (4F-PMA: 4-F-phenylmethylammonium) are characterized and compared. Using a combination of single-crystal X-ray diffraction, variable temperature time-resolved PL, and density functional theory, structure-property relations are correlated. Specifically, the results indicate that (4F-PMA)2PbI4 features stronger coupling to longitudinal optical (LO) phonons, assisting emission from a broad bound-exciton state due to a soft, deformable lattice. In contrast, (4F-PMA)2GeI4, benefitting from intermolecular bonding to scaffold a rigid octahedral structure, shows weaker LO-phonon coupling, resulting in the longest PL lifetime and most narrow linewidth (≈120 meV linewidth at 2 K) reported for a Ge-halide perovskite yet, without the occurrence of any additional bound-state emission at low temperatures. These results highlight the potential of germanium halide perovskite materials for optoelectronic applications |
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| Description: | Date Revised 28.04.2025 published: Print-Electronic Citation Status Publisher |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.202419879 |